Science form 5 notes
9.1 Classification of Microorganism
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Taxonomy "Five kingdom system of Classification":
Monera or Prokaryotae.
Prosita or protoctista
Fungi
Plant or plantae
Animals or Animalia.
Bacteria
Characteristics
The characteristics of bacteria are:
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Prokaryotic (no membrane-enclosed nucleus)
No mitochondria or chloroplasts
A single chromosome:
A closed circle of double-stranted DNA.
With no associated histones.
Classification of bacteria
Until recently classification was done on the basis of such traits as:
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Shape
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Bacilli:Rod-shaped
Cocci:Spherical
Spirilla:Curved walls
Ability to form spores.
Nutritional requirements.
Reaction to the Graim stain(bacteria cell wall).
Figure 9.1 structure of bacterial cell.
Table 9.1 shows the structure and function of a becterial cell.
Table 9.1
Reproduction
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A bacterium does not need a partner to reproduce.
Some bacteria can reproduce sexually,a process known as conjugtion (Figure 9.2).
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Figure 9.2
Conjugtion tube forms between a donor and recipient.An enzyme nicks the plasmid.
Plasmid DNA replication starts.The free DNA strand starts moving through the tube.
In the recipient cell,replication starts on the transferred DNA.
The cells move apart and the plasmid in each forms a circle.
Conjugation
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Sexual reproductive method.
Two bacteria form a conjugation bridge or tube between them.
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Photograph 9.1 Bacteria form a conjugation
DNA is transferred from one bacteria to the other.
Nutrition
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Autotrophic
Heterophic
Photosynthesis
Chemosynthesis
Heterotrophic
parasitic
Saprotrophic
Fungi
Characteristics
The characteristics of fungi are:
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Eukaryotic
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Do not contain chlorophyll.
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Do not photosynthesise
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Heterotrophs.
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Glycogen
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Most are saprophitic.
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Decomposers and recyclers.
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Multicellular.
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Internal or external parasites.
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Non motile
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Lack true roots,stems and leaves.
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Chitin.
Mycelia.
Edible.
Sexual and asexual spores.
Warm,Moist environments.
Mycology.
Fungicide.
Ondosymbiosis.
Reproduction
Non reproductive structures.
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Body of fungus is made of tiny filaments or tubes called Hyphae.
Cytoplasm and nuclei,chitin.
Photograph 9.2 hyphae.
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Septum (septa-plural) are cross walls with pores to allow the movement of cytoplasm in
hyphae.
Figure 9.3 Hypae
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Mycelium.
hyphae.
stolon
Rhizoids
Reproductive structure.
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Asexually and sexually.
Asexual reproduction genetically identical.
Sexual reproduction in fungi.
Asexually
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Mitosis
Budding
Photograph 9.3 Yeast.
Fragmentation
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Spores
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Penicillium produces spores Conidia without a protective sac on the
top of a stalk condiophore.
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Sporangium fungi
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Rhizopus stolonifer (Bread mold).
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Figure 9.4 bread mold
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Hyphae(Coenocytic)
Asexual.
Sporangium
Sporangispores
Rhizoids
Zygospores
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Figure 9.5 Sporangium fungi
Sexual reproduction in fungi.
Fungi reproduce sexually.
No male or female.
Plus (+) and minus (-)
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Fruiting bodies.asexual spores.
sporangiophore.sporangium
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Photograph 9.4 Sporangiophores
Spores: Dehydrated cytoplasm and a proctive coat.
Protozoa
Characteristic
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Prostista
Unicellular
Heterotrophs,Food vacuoles.
Way they move (cilia,flagella and pseudopodia).
Euglena
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Paramesium
Amoeba
Photograph 9.5 classification of protozoa
Microscopic
Zooplankton
Free living
Food for other organism,zooplankton
Reproduction
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Binary fission.
Multiple fission.
Sexually by conjugation.
Adaptations
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Eyespots
Conditions become unfavourable.
Detect and avoid obstacles and harmful chemicals.
contractile vacuoles.
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Protista
sarcodinians or pseudopodia.
silica or calcium carbonate.
Zooflagellates.
Ciliophorans or ciliates
Sporozoans.
Radiolarians
Pseudopods to surround the food.Phagocytosis.
Endocytosis.
Exocytosis.
Classificaton.
(a)Ameoba
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Contractile vacuoles.
Figure 9.5 structure of amoeba.
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Oxygen and carbon dioxide.
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cysts.
(b)Paramecium caudatum
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Slipper-shaped freshwater
Photograph 9.6 paramecium caudatum
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Pellicle is made of protein for protection
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Food
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2 contractile vacuoles
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Oral groove mouth
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Gullet into food vacuoles
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Wastes leave through anal pore.
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trichoysts.
Figure 9.6 structure of paramecium.
Figure 9.7 Formation of new paramecia
Algae
Characteristic
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Prostista
Autrophic
Plankton
Structure
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Thallus.
Phytoplankton.
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Chlamydomonas,volvox and spirogyra are example of algae.
Photograph 9.6 chlamydomonas
Photograph 9.7 volvox
Photograph 9.8 spirogya
Reproduction
Asexual phase
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Flagella
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Zygospore
Conjugation
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Photograph 9.9 Spirogyra cells
Sporangium
Sexual phase
Photograph 9.10 Conjugation tube between spirogya
Virus
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Nuclei acid and capsid.
capsomeres.
Figure 9.8 Examples of viruses
Inside
Structure
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TMV is rod-shaped
Measles,Rabies helical.
T-Phages head tail.
Bacteriophages or T-phages.
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Among the most complex viruses.
Attack bacterial cells
Tail fibres used to attach to host.
Photograph 9.11 T-phages structure
Retroviruses
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Reverse transcriptase helps use the RNA to make DNA.
Cause cancers and AIDS.
Photograph 9.12 hiv virus
Replication that rapidly kills the host cell causing it to lyse or burst.
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Absorpaiton,injection,replication,assembly and lysis.
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Absorpation:Phage attaches to cell membrane of host.
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Injection:Nuclei acid (DNA) of virus injected into host cell.
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Replication:Viral DNA inactivates host cell's DNA and uses host cell raw materials,ribosome,to
make viral DNA,capsids,tails and others.
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Assembly:New viral parts are combined to make new phages.
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Lysis:Enzymes weaken and destroy the cell membrane causing it to lyse releasing new
viruses to infect other cells.
Figure 9.9 Replication of virus
9.2 Factors that Affect Growth of Microorganisms.
Growth of microorganisms can be manipulated by controlling:
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Nutrient available.
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code.
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Oxygen.
Microbes also differ in their needs for free oxygen.
Organisms grow with or without oxygen.
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Water.
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water.
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Carbohydrate,fats,protein,vitamins,minerals,and water.
Enzyme system system are made available according to their genetic
Necessary for microbes to grow,but microbes cannot grow in pure
A measurement of the availability of water is aw or water activity.
Temperature.
Microorganisms can grow in a wide range of temperature.
Since they depend on water as a solvent for nutrients,frozen water
or boiling water inhibits their growth.
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Acidity and pH.
The nature of a solution based on its acidity or alkalinity is described
as the pH of the solution.
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The pH scale ranges from 0 which is strongly acidic to 14 which is a
strong alkali.
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Light and chemicals.
Ultraviolet light presence of chemical inhibitors also affect the
growth of organisms.
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Chemicals such as hydrogen peroxide and chlorine kill microbes.
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Growth.
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Characteristic growth patterns can be illustrated on a graph.
Normal growth curve which is referred to as the logarithmic growth phase or log phase.
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Figure 9.13 shows the useful of microorganisms.
9.3 useful microorganisms
Figure 9.13
The roles of useful microorganisms.
1.
Decomposition:
Syrophytic fungi and saprophytic bacteria decompose organic substances
into humus that contains simple minerals for plant growth.
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Figure 9.14 Decomposition
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Medicine:
Bacteria and fungi used in the production of antibiotics.
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Antibiotics are used to prevent the growth of other microorganisms
for the treatment of diseases such as gonorrhea,syphilis and tuberculosis.
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Agriculture:
Bacteria and fungi used in agriculture increase the amount nitrogen
elements and to recycle nitrogen.
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Nitrogen-fixing bacteria produce nitrates or ammonium salts causing
the nitrogen gas in the soil or air to chemically combine hydrogen,oxygen and
other elements.
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Industry:
Microorganism,yeast and bacteria used in food processing industries.
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Yeast added bread dough which contains carbohydrate starch and
glucose .beer,wine and brandy produced by the fermentation process using
yeast.
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9.4 Harmful microorganisms.
Diseases caused by microorganisms
diseases caused by bacteria
Diseases caused by fungi
The spread and prevention of infection droplet.
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Droplets spread the diseases causing organisms directly to another person.
Viral infection such as the common cold,influenza,and pneumonia are spread by droplet.
Contaminated water and food.
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Food and water can be contaminated causing organisms by sewage,contact wit people
suffering from diseases,by insect,birds and other animal.
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Typhoid fever,cholera ,and food poisoning are spread in this way.
Direct contact.
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Diseases by contact.
Smallpox,measles,and tuberculosis.
Animals
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Vectors.
Typhoid,cholera,dysentery germs.
Prevention of infection.
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Life cycles of pathogenic organisms and discovering how they enter the body.
More efficient sewage disposal methods for decontaming water supplies nd cleansing sites.
Ways to prevent infection caused by microorganisms
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1. Infection of diseases caused by microorganisms can be prevented by
Control of vectors
sterilisation
imunisation
Control of vectors
Control of mosquitoes.
Control of houseflies
9.6 Treating Diseases Caused by Microorganisms
Treatment of diseases
10.1 Evaluting the importance of taking good nutrition and practising good eating habits.
Nutrition
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Nutrition the study of materials nourish an organsim maintenance,repair ,growth and
reproduction.
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The food required for proper nutrition fall roughly into three major groups:
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Protiens
Carbohydrates
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Fats
Glycogen and fat.
Calorific values of the different classes of food.
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Maintain normal body temperature.
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All physical activities
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Maintain the action of the heart, blood circulation and respiration.
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Maintain chemical processes
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Calorific value total amount of energy released when one gram of the food is completely
oxidised.
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Bomb calorimeter(figure 10.1)
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Figure 10.1 a bomb calorimeter
The energy value of the three classes of food is shown in table 10.1.
table 10.1 energy value of one gram of carbohydrate,protien and fat .
Calculating calorific values in various meals.
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Joules ( J ) or kilojoules ( kJ )
1 calorie is equivalent to4.2 joule or 1 kilocalorie.
Energy value of different types of food.
Calculating daily calorific requirements of a student
Table 10.3
Factors affecting total calories required by an individual.
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Gender
Body size
Age
Physical activities
state of health
Climate
Table 10.4 shows the factors affecting the calorific requirement of an individual.
Gender
Table 10.5 shows the daily calorific requirments for both males and females at different ages.
Source:FAO - WHO 1974
table 10.5
Body size
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Individual with bigger body frames require more energy then those with smaller frames.
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This is because individuals with bigger frames need more energy to sustain their cellular and
metabolic process.
Age
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During the first five years of life,nutritional requirements,both of energy and other
nutrients,are relatively higher than adults.A child doubles its weights in the first six months of his
life.
physical activities
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Levels of physical activity.
(source : FAO - WHO 1994)
Table 10.6 The average daily energy requirements for male and female in relation to thier level of physical activity.
State of health
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Pregnancy increases the energy requirement of the mother by about 15%.
Mother will need more calories and balanced diet.
Infection and recovery.
Surrounding temperatures
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The surrounding temperature will affect the daily energy requirement of an individual.
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Who live in very cold climates like the eskimos may need more energy to keep warm and to
maintain basal body temperature compared to people living in the tropics.
Health problems related of nutrition
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Malnutrition,obesity,coronary heart diseases and diabetes mellitus.
Table 10.7
Health problem related to unhealthy eating habits
Overating or the absence of a 'balanced diet' is often observed in economically developed countries
indicated by increasing levels of obesity.
Obesity
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Obesity refers to an increase in body fat or an extreme degree of being overweight.
Treatment of obesity can be done by following a weight loss program which includes:
Exercise
A low-fat,high complexcarbohydrates and high fibre diet.
bahaviour modification to change eating habits
medications
Anorexia Nervosa
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Anorexia is a psychiatric eating disorder where people starve themselves.
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Anorexia usually begins in young people around the onst of pruberty.Anorexics mainly affect
adolescent girls.
Figure 10.4 A person suffering from
anorexia
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Psychological disorder.
Eating food high in cholesterol
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LDL(low density lipoprotein).
Plaque
Blood pressure
Heart attack
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Atherosclerosis
Elevates blood pressure.
Strokes.
Figure 10.5
Eating food high in triglycerides.
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Triglycerides are fats produced by the liver and are present in foods of animal origin.
Heart attack and atherosclerosis.
Eating food high in sugar
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Tooth decay
Photograph 10.2 tooth decay
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Diabetes mellitus
Ways to reduce the risk of diabetes are:
Eating a diet low in refined sugar and starch
Exercise and weight control.
10.2 Analysing the nutrient requirements of plants.
Photosynthesis and food production.
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Photosynthesis making things with light.
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chlorophyll
Figure 10.6 Photosynthesis
Macronutrients
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Macronutrients large quantities.
Nitrogen(N)
Rapid growth,increasing seed and fruit production improving the
quality of leaf and forage energy.
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Phosporus(P)
Transformation of solar energy into chemical energy.
help rapid growth.
Blooming root growth.
Potassium(K)
Building of protient,photosynthesis,fruit quality,enzymatic activity
and reduction of diseases.
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Calcium(Ca)
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Magnesium(Mg)
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Provides normal transport retention
Growth.
Soil minerals,organic materials,fertilisers and dolomitic limestone are
soures of magnesium for plants.
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Sulphur(S)
Production of protiens.
root growth seed production
plant macronutrient deficiency symptoms are as summarised below.
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Calcium (Ca)
Symptoms:New leaves are distorted or hook shaped.The growing tip
may die.Contributes to blossom end rotin tomatoes,tip burn of cabbages and
brown or black heart celery
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Sources: Any compound containing calcium and also gypsum.
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Notes:Not often a deficiency problem and too much will inhibits
other nutrients.
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Nitrogen(N)
Symptoms:Older leaves,generally at the bottom of the plants become
yellow.Remaining leaves are often light green stems may also yellow in colour
and may become spindly.slows the growth of plants.
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Sources: any compound containing nitrate,ammonium or urea and also
fertilisers.
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Notes:Many forms of nitrogen are water soluble and are easily
washed away.
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Magnesium (Mg)
Symptoms:slow growth and leaves turn pale yellow,sometimes just on
the outer edges.new leaves may be yellow in colour with dark spots.
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Sources:Compounds containing magnesium such as epson salts.
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Phosphorus(P)
Symptoms:Small leaves that may take on a reddish-purple tint.Leaf
tips can look burnt and older leaves become almost black.Reduced fruit or seed
production.
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Sources:compounds containing phosphate,bones and also green sand.
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Notes:Very dependent on pH range.
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Potassium(K)
Symptoms:Older leaves may look scorched around the edges or
wilted.Intervernal chlorosis(yellowing between the leaf veins)develops.
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Sources:Compounds containing potassium or potash.
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Sulphur(S)
Symptoms:New leaves turns pale yellow,older leaves stay
green.stunting of growth.
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Sources:Compounds containing 'sulphate'.
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Notes:More prevalent in dry wheather.
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Micronutrients
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Micronutrients smaller quantities.
The eight micronutrients,their functions and deficiency symptoms are as follows:
Boron
Chlorine
Cobalt
CopperIron
Manganese
Molybdenum
Zinc
Analysing the nitrogen cycle and its importance.
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Figure 10.9 The nitrogen cycle
Nitrogen cycle process atmospheric nitrogen converted ammonia nitrates.
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Ammonification
Nitrification
Denitrification
Figure 10.10
Process involved in the nitrogen cycle.
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Decompose proteins
Ammonification.
To produce nitrates for energy by nitrifying bacteria.
Denitrifying bacteria
Nitrogen fixing bacteria
Ammonium nitrates.
Figure 10.11 part of a clover root system bearing naturally occurring nodules of Rhizobium, bacteria
that can fix atmospheric nitrogen.Each nodule is about 2 - 3 cm.
Importance of the nitrogen cycle.
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Fixed,ammonium (NH4) and nitrate(NO3),
Nitrifying bacteria
Nitrogen fixation process.
10.4 Appreciating the importance of having good nutrition.
Benefits of healthy eating habits
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Healthy eating
Figure 10.12 A balanced meal
How to manage food resources and to avoid wastage.
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Droughts floods
malnourished
Excess food starvation.
11.1 Balance in Nature.
The role of natural cycles
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Balance in nature is achieved by the interraction between organisms and their
environment to meet their daily needs and to maintain the ecosystem at an potimum level.
The carbon cycles.
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Photosynthesis is represented by the equation below:
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Fossil fuels decay of organic substances by saprophytic bacteria and fungi.
Respiration is represented by equation below:
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Figure 11.1 shows the carbon cycle.
Figure 11.1 The carbon cycle.
The water cycle.
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Water cycle is the simplest natural cycle on Earth.It maintains the water content in
soil,oceans and in the atmosphere.
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Importance water cycle:
Maintains the aquatic habitats
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Provides water for rivers,lands,oceans and lakes
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Provides water to dissolve minerals in the soil for the
absorption by plants.
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Rain also makes the weather cool.
Figure 11.2 shows the water cycle.
Figure 11.2 The water cycle
The role of food webs.
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Food chain.
An example of a food chain os shown below:
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Figure 11.3 a Food chain
Producers
Primary consumer.
Secondary consumer
Tertiary consumer.
Decomposers.
Figure 11.4
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Food web.
Figure 11.4 shows a food web in a meadow.
Only 10% of the energy is actually transferred to next stages as shown in figure 11.5.
Figure 11.5 The transfer of energy in a food chain
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Feding relationship can also be represented graphically in the form of a
pyramid.pyramid of numbers is shown in figure 11.6.
Figure 11.6 A pyramid of numbers
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Food web controls the number of organisms in each level of the food chain.in this
way,balance in nature can be maintained.
The effects of natural disasters on balance in nature.
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Droughts,earthquakes,floods,typhoons(hurricanes) and Volcano eruptions.
Earthquakes
Volcano eruptions
Typhoons and hurricanes
Droughts.
Floods
Typhoons and huricanes
Volcano eruptions
Floods
Earthquakes
Drought
Figure 11.7 Examples of natural disasters.
Ways to maintain balance in nature.
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Controlling the excessive use of pesticides
Practising biological control of pests
Controlling deforestation
Preventing the hunting of animals
Controlling air and water pollution
Using biodegradable substances
Reducing the excessive release of carbon dioxide into the atmosphere
Education
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Three natural disaster which affect the balance in nature.
11.2 Environmental pollution
Sources of environmental pollution
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Pollution is defined as any undesirable physical,chemical or biological change of the
natural environment caused by the release of harmful substances due to human activities.
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Pollution can be catergorised as:
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Air pollution
water pollution
noise pollution
Thermal pollution.
Combustion of fossil fuels
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Fossil fuels are formed from the remains of animals and plants which have been buried
in the ground over hundreds of years.Formation of fossil fuels are shown in figure 11.8.
Figure 11.8 How fossil fuels are formed
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Factories and vehicles use fossil fuels such as coal,petroleum and natural gas to
produce energy.
Pollution from factories
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Various factories such as electronic and semiconductor factories produce by-products
that contain toxic metals such as cadmium,lead,nickel and mercury which cause metal poisoning.
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Various produce toxic substances such as cyanide which can poison aquatic organisms
when drained into rivers and seas.
Pollution from agriculture.
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Excessive use of chemical fertilisers:
Nitrates and phosphates stimulate excessive algae growth.Excessive
algae growth covers the surface of the water,prohibiting sunlight from
reaching the base of the ponds and rivers.
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Figure 11.9 shows eutrophication.
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Figure 11.9 Eutrophication in a pond
Excessive use of pesticides:
Pesticides such as herbicides, fungicides and insecticides are
used widely in the agricultural fild to control pests.
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Toxic substances can be carried by rainwater into ponds and
this raise the pesticide level in the water.Food chain when it is consumed by
smaller animals which are fed bigger carnivores and finally by human as shown
in figure 11.10.
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Figure 11.10 pesticides and its effect on the food chain
Vehicle and machineris
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The decibel (dB)is the unit used to measure the intensity of sound.
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Factories and vehicles release pollutants such as carbon dioxide,carbon
manoxide,oxides of nitrogen,sulphur dioxide,lead,hydrocaarbon and heavy metals.These air
pollutants are harmful.The health of humans can be afferected by these released pollutants.
Figure 11.11 Noise chart.
Disposal of rubbish
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Biodegradable rubbish.
Non-biodegradable rubbish.
Disposal of sewage
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Sewage is the liquid waste which is mainly made up of 99% water and 1% solid waste
from households(Kitchens,bathroom and toilet) and industries.
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Sewage includes human and animal faeces,detergents,domestic wastes and others.
Use of chlorofluorocarbons compounds.
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Chlorofluorocarbons (CFCs) are chemical compounds which contain only atoms of
carbon,chlorine and fluorine.
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Example of CFCs are
Dichlorodifluoromethane
trichlorofluoromethane
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Effect of environmental pollution
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Environmental pollution brings harmful effects on several aspects such as:
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Human health
Habitats and nature
The extinction of species
the loss of economic resources
Harmful effect on human health
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A clean and unpolluted environment is needed for good health of humans.
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Eyes,skin and respiratory system can be harmed by air pollution caused by the release
of smoke,poisonous gases and chemical substances.
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There are several sources of haze:
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Open burning of rubbish and agricultural wastes
Forest fires
Smoke from factories and coal - fired power generators
Exhausts fumes from motor motor vehicles.
Destruction of habitats and nature.
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Toxic substances and chemical fertilisers in water kill aquatic organisms.
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eutrophication can also result in the death of aquatic organisms.
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Acid rain causes the death of trees.As a result,organisms which depend on trees for
food and shelter lose their habitats.
The extinction of species

Extinction is a natural phenomenon or process which has been occurring since the
earliest forms of life evolved.

Destruction of habitats also cause some species to become extinct.Most species adapt
to a specific habitat to the environment which best meets their survival needs.the species may not
survive if they lose this habitat.
Loss of economic resources

soil pollution due to pollutants such as arsenic,lead, sulphur dioxide, fluoride and
residues from pesticides causes the soil to be unsuitable for agricultural activities.

Revenues lost due to pollution cause a decrease in aquatic plants and organisms.
Global warming

Global warming refers to an increase in the average temperature of the average
temperature of the earth's atmosphere.

Table11.1 shows the concentration of greenhouse gases in the atmosphere and its
sources.
Table 11.1

Green house gas acts like the glass surface of a greenhouse and reflects the heat
back to earth.this results in an increase in temperature
The greenhouse effect

This enough to warm up the earth to support life.This phenomenon is called the
greenhouse effect.

This results in an increase of Earth's temperature.This phenomenon is called global
warming.Warmer temperature causes the sea level to rise due to two reasons:


antarticaL
The ozone layer
Thermal expansion of seawater.
Melting of glaciers and ice sheets of greenland and the


Figure 11.12
Ozone molecule (O3) is made up of three atoms of oxygen as shown in figure 11.12.
Figure 11.13 shows the ozone production in the stratosphere.
Figure 11.13
The thinning of the ozone layer

The thinning of the ozone layer is due to the release of large quantities of
chlorofluorocarbons in the atmosphere.

In the stratosphere,UV rays breakdown CFCs to release active chlorine radicals.These
free chlorine radicals then break down ozone molecules in a series of actions as shown in figure
11.14.
Figure 11.14
Effects of the thinning of the ozone layer

The thinning of the ozone layer leads to significant increases in UV radiation reaching
the Earth's surface.

Ultraviolet radiations in large amounts are damaging to the growth processes of almost
all green plants.
11.3 Preservation and conservation of the environment and pollution control.
The importance of preservation and conservation of the environment

Preservation refers to the measures taken to keep living thing and the environment in
their original and balance state whereas Conservation refers to the careful and systematic use of
natural resources without bringing harm and death to living organisms in the environment.
Environmental pollution control

Controlling the use of fossil fuels
Figure 11.15 A catalytic
converter




Controlling
Controlling
Controlling
Controlling
the discharge of effluents from industries
the use of chemical fertilisers and pesticides
thermal pollution
rubbish and garbage disposal
Production of biogas from solid wastes is shown in figure 11.16.

Figure 11.16



Controlling sewage disposal
Controlling the use of chlorofluorocarbon
Enforcement of acts and regulations

table 11.2.
A few of these regulations and their functions are shown in
Table 11.2
Preservation and conservation of the environment for healthy and clean environment.

The environment that is free from air pollution is an environment with cleaner and
fresher air,no smog or haze and less acid rain is produced.

Concentration of oxygen and carbon dioxide in the environment canbe maintained by
controlling deforestion and reforestion.
Methods used to preserve and conserve the environment.





Setting aside protected areas
Enforcement of laws and regulations
Recycling and reusing materials
Banning the sale of products and medicines based on endangered species
Environmental education
11.4 The importance of proper management of natural resources in maintaining balance in nature

There is more demand for food supplies,water,homes and other basic needs since the
word's population increased.Therefore,activities such as agriculture and development are also
increased to cater to the increasing demand.
11.5 practising responsible attitudes to preserve and conserve the environment


Every individual is responsible in helping to manage the environment.
Reduce
Reducing the use of certain harmful materials which causes the
depletion of natural resources.


Recycle
Recycle is turning materials that would otherwise become waste
into valueable resources.


Reuse
Reuse is reusing old things for other purposes instead of
discarding them.We can reuse certain products by repairing them and donating
them to charity and community groups.


Producing compost:


Tree planting campaigns
Compost
12.1 Various carbon compounds






Carbon
Mineral carbonates,natural gas,oil and coal.
Graphite diamond.
Allotrophy
Graphite.
Photograph 12.1 Graphite
Diamond

Photograph12.2 Diamond
Charcoal
Organic Carbon compounds



organic
carbon,hydrogen and oxygen.
hydrogen and carbon are called hydrocarbon
Figure 12.1 examples of organic compounds
Inorganic carbon compounds





Major branches of inorganic compound groups include:
Minerals
Metal and their alloys
Non - metallic elements
Metal complexes
organic and inorganic compounds

Organic compound carbon and hydrogen

science of chemistry organic and inorganic
Comparison between organic and inorganic compounds
Figure 12.2 shows the comparison between organic and inorganic compounds .
Hydrocarbons






Hydrocarbons
Saturated hydrocabons
unsaturated hydrocarbons
saturated
unsaturated
combustion
Propane, an example of sturated hydrocarbon
Ethene, an example of unsaturated hydrocarbon
complete combustion

Burning or combustion is an oxidation reaction.When hydrocarbon burn
completely,the products formed are water and carbon dioxide.In general,the reaction is as shown
below:

Water (H2O) is an oxide of hydrogen.
Incomplete combustion


Carbon dioxide
Carbon monoxide, which is a poisonous gas with no smell (Figure 12.3).
Figure 12.3 Factory releases gases that can form posonous gas
ALKanes


CH4
The general formula for alkanes is:
CnH2n + 2

Each successive memner of the series has one more carbon atom than the
preceding member.this is shown in table 12.1
AlKenes

Alkenes
CnH2n

Double bonds
Table 12.1 saturated hydrocarbons
Table 12.2 unsaturated hydrocarbons
Differences between saturated hydrocarbons and unsaturated hydrocarbons
Table 12.3
SouRCE OF HYDROCARBONS
Coal,petroleum and natural gas


Fossil fuels
Non-renewable
Petroleum and natural gas


Petroleum,crude
Petroleum and natural gas
Fractional distilllation of petroleum



Fraction Refining.
Most volatile
Intermolecular force.



Less volatile
More viscous
Less flammable
Trends in properties
Oil fractions

Figure 12.4 summarises the main fractions from crude oil,their uses
and their properties.
Figure 12.4 The fractional distillation of crude oil.
HYdrOCARBOns chains
Coal


Photograph 12.3 Coal
Coal,carbon,hydrogen and oxygen.
Earth's crust.
AlcoHOL AND ITS effects on health
Elements in alcohol


Alcohol,Carbon,hydrogen and oxygen.
CnH2n+1OH,hydroxyl group.
Table 12.6 the first four alcohol members
Process of producing alcohol.




Ethanol,ethyl alcohol or grain alcohol.
Figure 12.6 structure of ethanol molecule
Molecular formula,empirical formula,C2H6O
Frementation
Yeast,ethanol and carbon dioxide.

yeast contains zymase enzyme which causes the starch or complex sugar to
break down to simple sugar (glucose)and then to ethanol and carbon dioxide.
IndUStrial production of alcohol


Figure 12.9 Ethanol preparation by hydration of ethene
C2H4
Hydration
General cHaracteristic of alcohol



Characteristics alcohol
colourless
Fruity odour
78oC
miscibles
Density less density water.
neutral
Veryflammable a pale blue flame.





Esterification

Esters

Esterification

catalyst

Sweet smelling
Table 12.7 shows some examples of the esters formed:
Table 12.7
USES OF ALCOHOL

Alcoholic drinks

Fuel

Cosmetic

Solvents
Effects of alcohol on health.

in low doses,alcohol:

Produces a relaxing effect
Reduces tension
Lowers inhibitions
Impairs concentration.
Slows reflexes
slows reaction time
Reduces coordination

In medium doses,alcohol:










Produces slurred speech.
Causes drowsiness.
Alters emotions.
In high doses,alcohol leads to:
Vomiting
Breathing difficulties
Unconsciousness
Coma




Effects of alcohol on the nervous system




Depressant
Addiction to alcohol and neurological problems.
Hallucinations and seizures
Chronic alcohol use can:
Damage the frontal lobes of the brain

Cause an overall reduction in brain size and increase in the
size of the ventricles

Effects of alcohol an pregnancy


Foetal alcohol syndrome
Facial deformities
SociAl Effects of alcohol

Alcohol decreases the drinker's inhibitions.Drinking can lead to inapproriate
social behaviours.

Alcohol abuse among workers can cause poor performances in their jobs.
12.3 Fats and their Effects on health













Fats Carbon,hydrogen and oxygen.
lipids or solid.
Saturated and unsaturated.
9 calories per gram.
Fatty acids.
Linoleic acid.
Animals and plants.
Saturated fat consists of triglycerides
no double bonds
Storage system and reserve supply of energy
Heat insulators body heat.
Lipids
Steroids and hormones.
Saturated and unsaturated fats.



Triglycerides ,glycerol with fatty acids.
Polyunsturated,monounsaturated
Dehydrogenations,Hydrogenations
Effects of consuming food rich in saturated and unsaturated fats on health.


Heart diseases.
Cholesterol.
What is cholesterol?


Fatty substances
Lipids
What is atherosclerosis?



Atherosclerosis
Reversible Changes
Irreversible changes atherosclerotic plaque chronic or acute.
WhAT DOES atherosclerosis do to the body?



Ruptures,heart attack or stroke.
Thrombose.
Hardening of the acteries.
12.4 OIL PALM AND ITS IMPORTANCE TO NATIONAL DEVELOPMENT
STRUCTURE OF AN OIL PALM FRUIT

Edible oils nutritional values.


A single seed,palm kernel,wooden endocarp or shell,mesocarp or pulp.
This fruit produces two types of oil:



Palm oil.
Palm kernel oil.
Cholestrol free.
Process of extraction of palm oil from the oil palm fruit.


contains:


liquid solid
Palm oil has a balanced ratio of unsaturated and sturated fatty acids.It
Oleic acid
Linoleic acid
Palmitic acid
Stearic acid


The processing of palm oil.

Crystallisation and separation.
Post harvest handling

case.
Oil extraction from oil palm fruit follows the same basic steps in either
Stripping fruit from bunches
Crushing,digestion and heating of the fruit.
Oil Extraction from macerated fruit using hydraulic



pressing.
Palm oil clarification
separating fiber from the endocarp.


uSES of palm oil.

applications.
Palm oil and its products are employed in numerous food and non-food
uses in the food industry

Margarine,shortening,soaps,oleochemicals and other products.
uSES IN NON-food products

categories:
Non-food uses of palm oil and palm kernel oil can be classified into two
Oil directly
Oleochemicals


Other uses and applications

High temperature tolerance does not oxidise rancid.

following:
The non-edible applications of palm oil and palm kernel oil include the







and metallic dryers.

Domestic soaps and detergents
Drilling mud for the oil industry
Gum
Candles
Cosmetics
Printing ink
Metallic soaps for the manufacture of lubricating greases
Fuels
Nutritional substances found in palm oil


Hard solid
Good HDL
the world's biggest palm oil producer

Malaysia currently accounts for 51% of world palm oil production and exports of
oils and 62% of world exports; 8% and 22% of teh world's total production and exports of oils
and fats respectively.
Research activities of palm oil in Malaysia
Function Of The malaysian palm oil Board (MPOB)

It assumes the functions previously undertaken by both PORIM and
PORLA and takes on new ones.Its functions are:
Conduct and promote research and development activities
relating to the palm oil and oil palm industries.

Regulate,register,co-ordinate and promote all activities
relating to the oil palm industries.

Develop and maintain markets for oil palm products as well
as promote efficient marketing.

Plan and implement training programmes and human
resources development in line with the needs of the oil palm industries.

12.5 The process of making soap from oil and the cleaning action of soap.
Composition of soap


Soap reaction fatty acid and a alkali.
Iye(hard soaps) potash.
Characteristic of the component of a soap molecule.




Long hydrocarbon end and short ionic end.
Non-ionic end repel water.
ionic,Attract water.
Micelles.
The cleansing action of soap molecules


Hydrophilic.
Hydrophobic
12.6 Natural polymers
The meaning of polymers








Polymer
Polymer large molecules many smaller and identical repeating units monomers.
Protein
Carbohydrates
The types of synthetic polymers includes:
Plastic
Fibres
Elastomer
Polymerisation and depolymerisation.




Polymerisation
Addition polymers
Condensation polymers
Polyamides
Natural rubber

A compound of hydrogen and carbon with the formula C5H8.It is called
polyisoprene or poly 2-methylbuta-1,3-diene.

Polyisoprene molecule,some 11 000 of these units are joined together end to
end to form a long chain.

In figure12.33.

unstretched rubber.

This is how polymer chain look like in a piece of
In figure 12.34

stretched rubber.
This is how polymers chains look like in a piece of
The action of acid and alkali on latex.

Latex is a colloidal solution containing rubber molecules,Water and non-rubber
materials.Each practicle in the latex is negatively charged and contains the rubber polymer
covered with a membrane of protein.
Effect of acid on the coagulation of latex.

As a result,the particles become nutral (no charges) and come closers and
collide with one another.

The collisions break open the colloidal membrane and release the rubber
polymers.

The lumps of rubber are white solids and elastic.
Effect of alkali on latex.


The coaglation of latex can be prevented by adding ammonia solution to latex.
Ammonia is an alkali and produces the hydroxides ions in its aqueous solution.
Vulcanisation of rubber.



The physical properties of rubber can be changed by vulcanisation.
Vulcaniosation hardening rubber.
Vulcanisation of rubber is carried out by
Heating natural rubber with sulphur at about 140oC,Using
zinc oxide as catalyst,or

Mixing a solution of sulphur monochloride (S2CL2) in
methylbenzene with natural rubber.

Importance of the rubber industry in national development.

The scop[e of research and development activities currently carried out on
natural rubber include the following:
To improve the quality of natural rubber

To find new uses of rubber and rubber products

To mechanise the tapping system in order to overcome
labour shortage and to save labour cost.

To propatage high latex producing clones.

To produce rubber clones that are resistant to plant
diseases.

12.7 Appreciating scientific research on the use of carbon compounds for the betterment of life.

Pure carbon has two allotropes,or different solid forms:Diamond and
graphite.The difference is caused by the way the atoms are arranged.

Diamond is a poor conductor of heat and electricity,it is 3.5 times as dense as
water.
Figure 12.40

touch.
The other carbon crystal,graphite,is soft,greyish black,slippery and cold to
Figure 12.41

Fluorocarbons are used as aerosol propellants and as a coating for non-stick
cooking utensils.

The special properties of steel are the results of adding carefully controlled
quantities of iron carbide to iron.
13.1 The motion of vehicles on land
The structure and principles of operation of vehicles without engines.

Sprocket and hubare two flat wheels with a row of teeth used to turn the
bicycle wheels and thus moving it.

The sprocket and hub are connected are connected by an iron chain.
The structure and principle of operation of vehicles with engines

An engine is a machine that converts chemical energy stored in fuel into kinetic
energy to produce motion.

There are three types of internal combustion engines,such as:

Four stroke petrol engine

Four stroke diesel engine

Two stroke petrol engine
The four stroke petrol engine


Four stroke petrol engines four cylinders.
Inlet valve,Exhaust valve and a spark plug.
Similarities and differences between the four strokes petrol engine and the four stroke diesel




diesel engine are
Internal combustion engine.
Four stages.
Convert chemicals energy to heat kinetic energy.
The differences between the four stroke petrol engines and the four stroke
as shown in table 13.3.
Table 13.3
The two stroke petrol engine.


There is no value in the two stroke petrol engine .
Table 13.4 shows the structure and operation of a two stroke petrol engine.
Table 13.4 The structure and operation of a two stroke petrol
engine
similarities and differences between the four stroke petrol engine and the two stroke petrol engine.





engine are shown
Internal combustion engines.
Petrol combustion fuel.
Spark plugs.
Convert chemical energy to heat kinetic energy.
The differences between the four stroke petrol engine and the two stroke petrol
in table 13.5.
Table 13.5
The relationship between the structure and operation of an engine and the movement of vehicles.


cylinder

When fuel burn internal combustion engines,hot gases are produced.
These hot gases expand and push the piston to move up and down in the
The force generated from the motion of the pistons is called the
engine power.
13.2 The concept of speed,velocity and acceleration


The distance is the total length travelled by an object.
The SI units of distance is metre,m.
Ticker timer

Ticker timer is a device used in the lab to study the motion of a moving object,
usually a trolley.A ticker timer consists of an electrical vibrator, which is connectedto an
alternating current (a.c) power supply (12 v or 6 v)

The ticker tape is attached to teh trolley which moves on the bench or runway.

The ticker timer can be used to determine the following:





Examples of tapes
Time interval
Displacement
Velocity
Acceleration
Type of motion
Figure 13.6
Examples of tape chart of moving objects

Constant velocity or zero acceleration

Increasing accelaration

Uniform deceleration

Uniform acceleration
13.3 the concept of inertia

suddenly.

Similarly,the passengers in a car will move backwards when the car accelerates

When a bus stops suddenly,the passengers experience a
forward jerk.

Figure 13.8 shows some examples of inertia.
As the lift start going down,we feel that we are left behind.
Relationship between mass and inertia

Every object has mass.The mass of an objects is the amount of matter
contained in the object.

The greater the mass of body,the greater its inertia will be.

Its is easier to push an empty trolley than one which is loaded.
A ship often takes over an hour to slow down to a stop because
of its large inertia.

An oil rig is able to stay afloats at its location even in rough
seas because of its large inertia.

The safety features used in vehicles





Seat belts(Safety belts)
Headrest
Air bags
`Crumple zone'
Restriction of the load
The applications of conservation of momentum

Principle conservation of momentum before a collision equal momentum after
collision provided.
The application of momentum in everyday life

The principles of conservation of momentum also applies to an explosion

Examples that involve impulsive forces are shown in Photograph 13.3
Photograph 13.3

The windscreen is made of materials that will crack but not shatter into many
small pieces in a collision.

Steel bars are used to withstand a large crashing force.
Pile driver

Pile driver is used in the piling process in the construction industry as shown in
Figure 13.12

as it falls, its velocity increases,hence increasing its momentum.

The pile driver works on the principles that increasing its mass and velocity will
increase its momentum.
Figure 13.12
Speed and weight limits for heavy vehicles.


Heavy vehicles have greater momentum due to their weights.
If heavy vehicles move at high speed, their momentum will be even greater.
13.5 the concept of pressure

The SI unit of pressure is newton per square metre (N m-2) or pascal (Pa).

High pressure is applied when cutting,sewing,hammering nails into wood and
when studs on the soles of soccer shoes sink into the ground.

For example,pressure exerted by a thumbtack as shown in figure 13.13.
Figure 13.13
The application of pressure in everyday life

Figure 13.16 shows the applications of pressure in daily life.
Figure 13.16
13.6 principles of hydraulic systems.

Figure 13.17 shows that water will spurt out through the openings when the
piston is pushed into the flask.
Figure 13.17

When the piston is pushed in,the water is compressed.The compression force
causes pressure to act on the surface of the water.
Principle of operation of a hydrolic system.

Hydraulic system,small force produce larger force.

Figure 13.19 shows a simple hydraulic system.

As the pressure is transmitted uniformly,

The output force F can be obtained ny the following formula:
Figure 13.19
Application of the hydraulic system in daily life.

car.
Figure 13.20 shows a hydraulic jack.The hydraulic jack is used to lift
Figure 13.20

The large piston can be lowered at the end by opening the release
fluids to flow back into the buffer tank.
Hydraulic brake

Hydraulic brakes

Figure 13.21 shows a hydraulic brake system.
Figure 13.21
13.7 The motion of vehicles in water

Most of the fluids flows past the front of this shape and there is very
little turbulence at the back.
Figure 13.22

When an objects is in water,the water will exert an upward force called
the upthrust on the object.
Archimedes' principle and its application in everyday life


in the sea.
Archimedes' upthrust on the object equal weight of the fluid.
Photograph 13.4 shows even though the ship is very heavy,it can float

Figure 13.24 shows a submarine that can float or sink in water.
photograph 13.4 A ship
Figure 13.24

Photograph 13.5 shows a hydrofoil with two sets of foils at the front
and at the back.
Photograph 13.5 A hydrofoil

Hovercrafts,shown in photograph 13.6 are vehicles that travel along a
cushion of air at high pressure.
Photograph 13.6 Hovercraft
13.8 the motion of vehicles in the air.

Figure 13.25 shows a balloon filled with hydrogen or hot air and its
weight is less than the weight of air it displaces.
Figure 13.25 A hot air balloon

Figure 13.26 shows an airships filled with hydrogenor helium often
powered by engines which drive propellers that provide vertical thrust and landing and
horizontal thrust for forward motion.
Figure 13.26 an airship

A rocket has separate tanks containing liquid oxygen and liquid
hydrogen as shown in figure 13.27
Figure 13.27 A rocket

A jet engine (Figure 13.28) Doesn't need a supply of liquid oxygen.
Figure 13.28 a jet engine

table 13.13
The differences between the jet engine and the rocket are shown in
Table 13.13
Bernoulli's principle and its application in air.

A filter funnel is inverted and a ping pong ball is held under it as shown
in figure 13.29.
Figure 13.29

A thin sheet of paper is held in a horizontal plane in front of the lips as
shown in figure 13.30.

rise.
Figure 13.30
Air is blown across the top of the paper.the free end of the paper will

Air is blown vigorously between the two sheets of paper held vertically
as shown in Figure 13.31

Figure 13.31
The two sheets of paper are pressed together by the outside air.
THE APPLICATION OF BERNOULLI'S PRINCIPLE IN FLIGHT.

13.33
Its top surface is curved while the bottom is flat as shown in figure

aerofoil.
Cross section of an aeroplane's wing which has the shapeof an

Aeroplane

Figure 13.33.
There are four forces acting on an aeroplane as shown in figure 13.34.
Figure 13.34 Forces that act on an aeroplane in air.
13.9 Appreciating the ability and creativity of mankind in inventing and designing vehicles for the betterment of life.



Good habits:
Make sure the vehicles are in good working condition.
Obey all the safety procedures and rules when using vehicles.
14.1 Methods and substances used in food technology




Food technology
Processed food
Food processing
Purpose of processing food:
To destroy microorganisms and pathogens in the food so
that food is safe for consumption.

To extend the lifespan of food.

More digestible.

Taste of food

Increase the nutrient content of food.

Increase the commercial value.

Types and function of chemicals used in food processing.

Various types of chemicals are used in food processing.These are:
Preservative
Colouring
Bleach
Flavouring
Stabiliser
Sweetener
Antioxidant
Emulsifier








Technology in food processing and packaging



Technology
Food processing
Food packaging
Technology used in food processing
Pasteuristion



Pasteurisation processes liquid food.
63oC for 30 minutes.
72oC for 15 seconds.
Dehydration


Dehydration removing water.
Dehrdration can be carried out by:
Spray Drying
Vacuum packaging
Drying food in the sun
Using smoke to dry food.




Freezing

Freezing a very low temperature.

Frozen food lasts longer.Meat and fresh fish are examples of food which can be
stored in this way.
Freeze drying


Cooling


for a short time.
Irradiation



Freeze drying
Less than -18 oC.Evaporated vacuum condition.
Cooled 0 oC to 10 oC.
Thus,this reduces the decomposition rate of food by microorganisms but only
Irradiation exposed radioactive radiation.
Table 14.2 below shows the dose categories and their function or irradiation.
Table 14.2
Benefits of irradiation of food include:


Since no chemicals are added to food,irradiation is safe.
Irradiation controls the quality and cleanliness of food.
Technology used in food packaging
Canning

Canning pack and preserve food in tins.

Little salt or sugar 10.5 kPa at temperature of 121 oC for 20 minutes.
Vacuum Packaging

Vacuum packaging removing all the air.

packed foods.
Table 14.3 shows the shelf life of some vacuum packed food non-vacuum
Table 14.3
Effect of excessive use of chemicals in food processing.


table 14.4.
The food Act 1983.
The effect of the excessive use of chemicals in food processing are shown in
Table 14.4
14.2 Ways of improving food production.
The need to increase the quality and quantity of food production.

The population of malaysia increased from 10.5 million in 1970 to 17.5 million
in 1990.In 2006,the population of malaysia was 26.6 million.

The increase in food production must correspond with population growth as the
growing population needs more food.
Ways to increase the quality and quantity of food production
Use of quality breeds

Abundant harvest

Fast ripening of fruits

High quality produce

Good resistance to diseases or pest attacks.

MARDI and MPOB

Many crops in malaysia are produced by MARDI.Examples are:



MDUR 88 durians
Jalomas sweet potatoes.
Melomas pomeloes.
MELOMAS pomeloes
JALOMAS sweet potatoes
Figure 14.1 Various new crops planted in malaysia
Use of modern technology


Modern machinery and biotechnology.
Biotechnology techniques include:
Cloning is the process of creating an identical copy of

something.
Dolly a finn Dorsett ewe,was the first mammal to have
been sucessfully cloned from adult cell at roslin institute in the United
Kingdom.

Photograph 14.1 Bottles containing young plants produced
through cloning.




Genetic engineering
Selective breeding
Embryro transfer technique
Artifical insemination
Education and guidance for farmers.



(Fama)Veterinary services
Purpose of research
MARDI,MPOB AND FAMA
Optimum use of land and irrigated areas.



FELCRA
FELDA
LKIM
Efficient land management.





Terracing
Contour planting
Adding fertilisers.
Cover crop planting system.
An intergrated system.
Genetically modified food(GM Food)


Genetically modified food
Genetically modified organisms


In genetic engineering
Genetically modified food
Advantages and disadvantages of GM food
Advantages of GM food.

Increase crop yields

Increase tolerance of crops

Improve nutrient composition

Resistance to crop pests

Appeatance,flavour nutritional values

Solve shortage of food.
Disadvantages of GM food.





Influence normal genes
Health risks
Environment distrupted
Damage human health
Attack normal crops.
14.3 Contribution of technology in food production for the betterment of life.
The research and Development(R&D) activities of food production

Some instituitions involved in R&D activities of food production in malaysia are
shown in table 14.6.
Table 14.6

technology.
The quality and quantity of food production has been increased using
An imbalance between population increase and technological development in food production.


factors:




sectors.
World population growth pattern in the last 2000 years is shown in Figure 14.2.
Figure 14.2
The rapid increase in the world population is caused by the following
World peace
Industrial revolution
Progress in the field of medicine
Development in the agriculture and animal husbandry

progression.
Thomas malthus (1766 - 1834),world population increases in geometric



Starvation
Cannot obtain sufficient food.
Malnutrition


Insufficient nutrition
Improper diet.
14.4 Practising Critical and analytical thinking in the selection of processed food.
Food act and food regulations

The Food Act (1983) and the food regulation(1985) are laws which involve food
and public halth in Malaysia.
The food act 1983

Food Act 1983(Act 281)

Food manufacturers can be charged under section can be charged under section
13 of the food Act if they are found preparing or selling food which.

consumers.
Contain any poison that can affect the health of
Is produced from animals that are diseased or dead other
than from being slaughtered.

Figure 14.3 An example of a food label.




Statutory authorities:
Test food
Ascertain food prepared
Control price
Food regulations 1985.







Name of food
Ingredients
Quantity of food
Expiry date.
Food storage instruction
Name and address of the manufacturer
Weights,volume or quantity of content
Educating consumers to be critical and analytical when selecting processed food.
















Consumers
Consumer education
Consumers' rights according to the food to the food Act 1983 are as follows:
Security right
Right to obtain information
Right to choose
Right to buy a product at a reasonable price.
Right to seek compensation
Right to report
Right to get due consideration on his report.
Right to get consumer education
In A formal manner
In an informal manner.
Guidance choosing processed foods.
Ingredients
Good condition
Latest Information

The need to educate consumers in selecting processed food.

Consumers need to be educated on their rights and also their rights and also
their responsibilties.

It is necessary to create a pool of consumers who are rational and always
careful when buying food products.
Synthetic polymers



Synthetic polymers man-made polymers.
Petrochemicals.
There are three main groups of synthetic polymers:
Plastics
Synthetic fibres
Synthetic rubber



Uses of synthetic polymers


Plastic
Table 15.1 shows a list of synthetic rubber,Their properties and uses.
Table 15.1


Nylon
Terylene
Process of making polymers

Polymerisation is a process whereby two or more simple molecules are linked together
to form a larger molecule.The smaller molecules while the complex molecules are known as
polymers.A polymer chain may contain as many as a few million monomers joined together
(Figure 5.1)

Table 15.2 shows a few examples of polymers and thier monomers

Polythene or polythylene is the simplest synthetic polymer.
Process of making synthenic rubber

Synthetic rubber is produced in a number of ways.Figure 15.2 illustrates one common
production process.

Fractional distillation of crude oil produces shorter chains such as naptha.Naptha is
then converted into monomers such as butadiene,ethylene or propone

The subsequent polymerisation process results in a wide range of synthetic rubbers
with different applications as well as varied chemical and mechanical properties.
General chracteristics of synthetic rubber in relation to its uses

Synthe tic rubbers are artificially produced have properties similar to natural rubber
have unique properties not found in natural rubber.

Nevertheless,synthetic rubber may not be a elastic and stretchable as natural
rubber.Furthermore,synthetic rubber does not absorb sounds,friction and pressure as well as
natural rubber.

By combining the properties of both natural and synthetic rubber,scientists are able to
make many new products.

The following examples show some characteristics of synthetic rubber in relation to its
uses.
Elasticity


Rubber has excellent elastic properties.
It is this property makes rubber bands so useful.
Examples of rubber materials
Resistance to attack by chemicals

Synthetic rubber resists attack be chemicals such as oils and petrol.This property is
useful in industrial situations such as those where oiland petrol are involved.

The hoses at petrol pumps are made from synthtic rubber.
Impermeable

Rubber is non-porous material.
Figure 15.3 Tennis ball
Texture

Fairly soft materials

Friction is needed beetween the soles of shoes and floors,tyres and roads and hands
and tennis rackets.
Figure 15.4 Tennis racket
Electrical insulation

Electrical insulating
Photograph 15.2 rubber shoes
Hardness

Tough
Figure 15.5 Golf ball
Firmness

Floppy material.
Photograph 15.3 Belts for pulley system.
Easy to be vulcanised

Tyres are made from a combination of both natural and synthetic rubbers.The natural
rubber is vulcanised by adding sulfur molecules.
Photograph 15.4 Tyre
Examples of goods made from synthetic rubber.

The following are examples of good made from synthetic rubber.
a) Stoppers and caps
b) Gloves
c)Silicone rubber bracelet
d)Silicone rubber cable
e)Elbow supports for tennis players
f)Tyres
Photograph 15.5
Examples of goods made from a combination of natural and synthetic rubber.

Natural rubber is too soft,melts easily when hot and has been known to cause allergy
in human beings.
Comparing and contrasting between natural rubber and synthetic rubber

rubber.
Table 15.3 below shows comparison between properties of natural and sythetic
Table 15.3
15.2 Analysing plastics
Plastics



Moulded squeezed, cast or squirted.
Polymerisation.
Table 15.4 shows examples of plastics and their uses in daily life.
Table 15.4
Types of plastics



Thermoplastic
Reheated and remoulded
Flexible
Figure 15.6 polymers molecules in thermoplastics
Characteristics of thermoplastics




Good insulators of heat and electricity
Resistant to chemicals like acids and alkali
Can dissolve in organic solvents.
Transparent and colourless
Thermossets

Cross-linked together.
Figure 15.7 Polymer molecules in thermosetts plastics.
Characteristics of thermossets




Good insulators of electricity
Durable and long lasting
Chemically inert and resistant to corrosion
Does not dissolve in any organic solvents.
Comparison between thermosplastics polymers with thermosetts polymers.
Table 15.5
Potential uses of plastics.




Hi-tech industries
Composites
In the field of medicine,plastics are being used:
To replace arteries in the heart.
To replace torn cartilages and ligaments.







Bionic ears
Aramid
Polycarbonates
Mylar
Nomex
New contact lenses are made from co-polymers plastics(PMMA) and slicone.

Extremly tough.
Photograph 15.7 contact lense.
Photograph 15.8 Coating of new plastics used in ipods.
Effects of improper disposal of plastic materials on the environment

Improper disposal of plastics can cause environmental pollution because:


Air pollution




Non-biodegradable
High toxic gases hazardous.
Acid rain
Global warming greenhouse effect
Water pollution marine life.
Proper management of disposal of plastics


Reduction of the amount of plastics used.
Recycling of plastics.




A warning label.
practise and promote.
Reuse of plastic bags.
Invent and use bidegradable plastics.
15.3 Practising Responsible Attitudes in the disposal of synthetic.

Today,synthetic polymers such as wood,silk,clay,wool and latex.synthetic
polymers are used because of their advantages such as:




Cheap
Strong and light
Resistant to chemicals.
Durable.
Ways to dispose synthetic polymers

Recycling of synthetic polymers:
Different types of synthetic polymers can be sorted out and
placed into different bins for recycling.


Biodegradable or organic polymers:
Polylimonene carbonate,an environmentally freindly polymer
made from orange peel oil can replace polystyrene


Reuse of synthetic polymers:
Plastic bags made from synthetic polymers should be used as
many times as possible thus,curtailing their production.

Practise good habits in disposing synthetic polymers.

It is the responsibility of every individual to practise proper disposal of synthetic
polymers and help to conserve the environment.
Synthetic polymers






Synthetic polymers man-made polymers.
Petrochemicals.
There are three main groups of synthetic polymers:
Plastics
Synthetic fibres
Synthetic rubber
Uses of synthetic polymers


Plastic
Table 15.1 shows a list of synthetic rubber,Their properties and uses.


Nylon
Terylene
Table 15.1
Process of making polymers

Polymerisation is a process whereby two or more simple molecules are linked together to
form a larger molecule.The smaller molecules while the complex molecules are known as
polymers.A polymer chain may contain as many as a few million monomers joined together
(Figure 5.1)

Table 15.2 shows a few examples of polymers and thier monomers

Polythene or polythylene is the simplest synthetic polymer.
Process of making synthenic rubber

Synthetic rubber is produced in a number of ways.Figure 15.2 illustrates one common
production process.

Fractional distillation of crude oil produces shorter chains such as naptha.Naptha is then
converted into monomers such as butadiene,ethylene or propone

The subsequent polymerisation process results in a wide range of synthetic rubbers with
different applications as well as varied chemical and mechanical properties.
General chracteristics of synthetic rubber in relation to its uses

Synthe tic rubbers are artificially produced have properties similar to natural rubber have
unique properties not found in natural rubber.

Nevertheless,synthetic rubber may not be a elastic and stretchable as natural
rubber.Furthermore,synthetic rubber does not absorb sounds,friction and pressure as well as
natural rubber.

By combining the properties of both natural and synthetic rubber,scientists are able to make
many new products.

The following examples show some characteristics of synthetic rubber in relation to its uses.
Elasticity

Rubber has excellent elastic properties.

It is this property makes rubber bands so useful.
Examples of rubber materials
Resistance to attack by chemicals

Synthetic rubber resists attack be chemicals such as oils and petrol.This property is useful in
industrial situations such as those where oiland petrol are involved.

The hoses at petrol pumps are made from synthtic rubber.
Impermeable

Rubber is non-porous material.
Figure 15.3 Tennis ball
Texture

Fairly soft materials

Friction is needed beetween the soles of shoes and floors,tyres and roads and hands and
tennis rackets.
Figure 15.4 Tennis racket
Electrical insulation

Electrical insulating
Photograph 15.2 rubber shoes
Hardness

Tough
Figure 15.5 Golf ball
Firmness

Floppy material.
Photograph 15.3 Belts for pulley system.
Easy to be vulcanised

Tyres are made from a combination of both natural and synthetic rubbers.The natural rubber
is vulcanised by adding sulfur molecules.
Photograph 15.4 Tyre
Examples of goods made from synthetic rubber.

The following are examples of good made from synthetic rubber.
a) Stoppers and caps
c)Silicone rubber bracelet
e)Elbow supports for tennis players
b) Gloves
d)Silicone rubber cable
f)Tyres
Photograph 15.5
Examples of goods made from a combination of natural and synthetic rubber.

Natural rubber is too soft,melts easily when hot and has been known to cause allergy in
human beings.
Comparing and contrasting between natural rubber and synthetic rubber

Table 15.3 below shows comparison between properties of natural and sythetic rubber.
Table 15.3
15.2 Analysing plastics
Plastics



Moulded squeezed, cast or squirted.
Polymerisation.
Table 15.4 shows examples of plastics and their uses in daily life.
Table 15.4
Types of plastics



Thermoplastic
Reheated and remoulded
Flexible
Figure 15.6 polymers molecules in thermoplastics
Characteristics of thermoplastics




Good insulators of heat and electricity
Resistant to chemicals like acids and alkali
Can dissolve in organic solvents.
Transparent and colourless
Thermossets

Cross-linked together.
Figure 15.7 Polymer molecules in thermosetts plastics.
Characteristics of thermossets




Good insulators of electricity
Durable and long lasting
Chemically inert and resistant to corrosion
Does not dissolve in any organic solvents.
Comparison between thermosplastics polymers with thermosetts polymers.
Table 15.5
Potential uses of plastics.




Hi-tech industries
Composites
In the field of medicine,plastics are being used:
To replace arteries in the heart.
To replace torn cartilages and ligaments.







Bionic ears
Aramid
Polycarbonates
Mylar
Nomex
New contact lenses are made from co-polymers plastics(PMMA) and slicone.

Extremly tough.
Photograph 15.7 contact lense.
Photograph 15.8 Coating of new plastics used in ipods.
Effects of improper disposal of plastic materials on the environment

Improper disposal of plastics can cause environmental pollution because:


Air pollution




Non-biodegradable
High toxic gases hazardous.
Acid rain
Global warming greenhouse effect
Water pollution marine life.
Proper management of disposal of plastics




Reduction of the amount of plastics used.
Recycling of plastics.
A warning label.
practise and promote.


Reuse of plastic bags.
Invent and use bidegradable plastics.
15.3 Practising Responsible Attitudes in the disposal of synthetic.

Today,synthetic polymers such as wood,silk,clay,wool and latex.synthetic polymers
are used because of their advantages such as:




Cheap
Strong and light
Resistant to chemicals.
Durable.
Ways to dispose synthetic polymers

Recycling of synthetic polymers:
Different types of synthetic polymers can be sorted out and placed
into different bins for recycling.


Biodegradable or organic polymers:
Polylimonene carbonate,an environmentally freindly polymer made
from orange peel oil can replace polystyrene


Reuse of synthetic polymers:
Plastic bags made from synthetic polymers should be used as many
times as possible thus,curtailing their production.

Practise good habits in disposing synthetic polymers.

It is the responsibility of every individual to practise proper disposal of synthetic polymers and
help to conserve the environment.
8.1 Properties of alloys and Their uses in industry.
Alloys






Homogenuos mixture pure metal another pure metal or Non metal.
Alloying mixing other elements to the pure metal.
Alloying process is carried out as follow:
A pure metal is melted
some metal and non-metal are then added to the molten metal
The mixture is the cooled
Table 8.1
Alloying Changes the properties of metals.

Weakness and structure of a pure metal are improved by alloying.

Pure metals become more resistant to corrosion,shinier,more attractive appearance and
harder.
Prevents corrosion of metals.

Alloying.
Improves the appearance of metals.



Copper has dull brown surface after being oxidised.
Alloying prevents rust,most alloys,nice shiny surface.
Examples:
A little nickel is added to copper to produce copper nickel alloy.

Increases the hardness and strength of metals.



Metal such as magnesium,aluminium are soft and light.
Problem can overcome by alloying.Alloys are harder and stronger.
For example:
Magnesium is mixed with aluminium to produce magnalium.Magnalium
is an alloys are hard but it still retains the lightness of both these pure
metals.

Arrangement of particles in alloys and the uses of alloys
1.
Atoms of pure metals are arranged very closely and orderly as shown in figure 8.1.
Figure 8.1
2.The layers of atoms slide easily over one another when a force is applied.as a result,it
becomes ductile as shown in figure 8.2.
Figure 8.2 Ductile property of metal.
3.Ability of the layers metal atoms to slide easily also makes it malleable and easily shaped when
a forced is applied as shown in figure 8.3.
Figure 8.3
In an alloy,substances added which are smaller or bigger fill the shapes between the pure metal
atoms and the new arrangement is formed as shown in figure 8.4.
Figure 8.4 Alloy with smaller atoms.

Prevents the layers of pure metal atoms from sliding over one another.
Table 8.2 shows the comparison between a pure metal and alloy.
Table 8.2
The importance of alloys in industry.


Carbon steel.
Stainless steel resistant to corrosion.
Supercondutor alloys.

Differences ordinary conductor(Normal conductor) and superconductor.
Figure 8.5
Table 8.3 shows uses of superconductor alloys in industry and daily life.
Table 8.3
8.2 Production and uses of ammonia in industry.
Ammonia.


Pungent smell,colourless and very soluble in water.
ammonium hydroxide.
Uses of ammonia and its compound in daily life.

Table 8.4 shows uses of ammonia and its compounds in daily life.
Table 8.4
Production of ammonia in industry.



Haber process produce ammonia.
Nitrogen and hydrogen.
Hydrogen is produced by reacting methane with steam or from the cracking oil.


Iron powder is added as a catalyst.Booster like aluminium oxide.
The following shows the reaction in producing ammonia.

Reversible.

Figure 8.6 The haber Process
Factor influencing the production of ammonia:
Pressure 200-500 atmospheres.

Temperature Exothermic 450-500ºC

Catalyst increase the rate of a chemical reaction boosters activate
the catalyst.

Uses of ammonia in industry.

Ammonia is also used in large quantities to produce Nitric acid.
Production of ammonium fertilisers.


Natural fertiliser.
Synthetic fertiliser.

Ammonium nitrate

Ammonium sulphate

Ammonium phosphate

The preparation of ammonium salt fertiliser in the science laboratory is as follows:
Production of ammonium salt fertilisers.
Production of urea.





Urea is produce through the following processes:
Heated 200ºC and pressure of 200 atmospheres.
Separated
dried
The reaction between chemicals which produce urea is shown below.
8.3 Effects of industrial waste disposal on the environment.

Poisonous and harmful industrial activities causes the quality of the environment to be on the
decline.

the two main pollution-causing industrial activities are:


The burning of fossil fuels.
the direct disposal of industrial wastes from facrtories.
Sources of pollution from manufacturing activities and the effects of imporer industrial waste disposal .
Burning of fossil fuels.

Fossil fuels such as diesel,oil and natural gas are burned in factories and electric
power stations to generate heat energy and electrical power.

Gases such as carbon dioxide,carbon monoxide,sulphur dioxide,and nitrogen dioxide are
released.because fossil fuels have high contents of carbon and sulphur.
Greenhouse effect.

Earth receives most of its energy from the sun.Energy is used to heat up the Earth's
surface.Heat produced is in the form of infrared radiation.It reflects heat back into the
atmosphere.70% of the sun's energy is radiated back into space.Earth is kept warm enough to
support life.

Increase Earth's temperature by trapped heat in the atmosphere as shown in figure 8.8.
The greenhouse effect also causes other problems such as:

The weather becomes warmer.

The melting of ice.

desert areas bigger.

Global warming.
Figure 8.9 shows the contribution of different types of greenhouse gases towards global warming.
Greenhouse gases that contribute
towards global warming
Acid rain
sulphur dioxide contributes to acid rain
The effects of acid rain:

Disturbs the equilibrium of nature

Acid rain affects lakes,streams,rivers,bays,ponds and other sources by increasing their
acidity.This leads to the death aquatic organisms and plants.

Destroys plants and trees as the soil becomes too acidic.
Chemical industry.


Toxic chemicals,oils and untreated waste.
Pollutants also affect quantity of dissolved oxygen,affecting aquatic animals and plants.
Nuclear power stations and research institutions.

Radioactive produced nuclear research centres,nuclear reactors and manufactring products
contain radioactive substances.

Radioactive radiations released by these sources into the surrounding.
Agriculture industry.

Oil palm industry

spill.

rot.

Oil palm industry are stalks of fruit branches,fibre wastes and oil
Oil palm wastes are disposed off by burning them or leaving them to
Rubber industry

protein.
Rubber wastes are made up of phospate salt,ammonia and rubber

These wastes encourage the growth of bacteria.
Table 8.5 shows the types of pollutants,their sources and effects on living organisms.
Table 8.5
Method of controlling industrial waste disposal.
Several ways to control the disposal of industrial wastes such as:

Law enforcement
Environmental Quality (scheduled wastes)Regulation,1989
Environmental quality (Clean air)Regulation,1979



Recycling wastes
Variety of industrial wastes recycled for use as products.

Particulars industry can also be used by other industries if that
industries if that industrial waste is suitable for them.


Education
Public need to be educated about the importance of environmental
cleanliness and the harmful effects of environmental pollution.

The mass media and schools plays important roles in spreading
environmental awareness to the public.


Technology
Biogas technology
direct burning
Disposal drums
Using electrostatic precipitator
Using a scrubber





Biogas technology





Process agricultural wastes naturally through digestion by microorganisms.
Anaerobic microorganisms.
Inside a digester drum called the Digester unit.
Temperature 30 ºC - 40 ºC
Biogas.
Figure 8.12 biogas digester

The separated methane is sent to houses for cooking purposes or to factories for Heating
purpose.

Electrical energy.
Direct burning


Agricultural wastes are directly burned in a heating furnace.
Figure 8.13 shows the system which is used to burn agricultural wastes.
Figure 8.13 Component of the direct burning system.
Disposal drum

Radioactive waste is radioactive material which may be left after a commercial or laboratory
process has been carried out.

Radioactive wastes disposal drums which are made of strontium.

Disposal drums placed 200 metres below the soil surface.
Using electrostatic precipitor.



Electrostatic precipitator two collection plates:
Positive plate
Negative plate
Using a scrubber.


Scrubber is used to filter the poisonous gases by sparing a liquid onto the poisonous gases.
The toxic-free gas is then released.
air scrubber.
8.4 Preservation and Conservation of the Environment.

Preservation Environment refers to steps taken to maitain the environment as close to its
Natural state as possible.

Conservation refers continuos managment of the environment to minimise damage to the
environment.
Consequences of uncontrolled and haphazard disposal of industrial wastes.

Earth is in real danger.This can be proven through headlines in newspapers about the
uncontrolled and haphazard disposal of industrial wastes.

Indusrtrial wastes can pollute water sources.Water sources become unsuitable for human
consumption.Water pollution also threatens aquatic lives.
The importance of practising responsiblity in disposing wastes.

Humans must practice responsibility.

All wastes produced by industries must be stored,transported and disposed off properly.

A pollution-prevention hierarcy which emphasies on reducing the amount of toxic waste
produced as shown in figure 8.15 must be implemented .stratergies involved include:




Reduce the amount of pollution at the source.
Recycle wastes wherever possible.
Treat wastes to minimise their hazards.
Disposal of wastes on land is carried out only as a last resort.
the pollution-prevention hieracy




Several ways to preserve and conserve the environment which include:
Control by authorities.
Education.
Use of technology.
Control by authorities.



The following laws are used to control the disposal of industrial wastes:
The Environmental Quality act 1974(Amendment 1985).
The Factory and machinery Act 1976(Revised 1983).
The pest Poison Act 1874


The government organised and participated in international conferences to discuss
environmental world issues.There are:



The langkawi declaration (october 1991).
The Earth summit conferences (1992).
The agreements made in this conferences include:

warming.

extinct.





Reducing the emission of carbon dioxide gas that causes global
The protection of animals and plants to ensure they do not become
The Earth summit resulted in the following documents:
Agenda 21
convention on biological diversity
Forest principles
Rio declaration on Environment and development.
Educating the public.

Every citizen has a responsibility in looking after the cleanliness and purity of the
environment.

The preservation and conservation Environment can be spread through campaigns,mass
media and the school syllabus.
Use of technology.


Pollution reduced by using modern technology.
Factories reduce pollutants in the air by installing filters.