By:- Fahad Ali Ranjhani Junior’s Science Club Dadu 03112194596 –adon387@yahoo.com
The Cell
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Cell History
The study of cells is called cytology.
Robert Hooke was the first scientist to use the word cell.
Robert Brown discovered the nucleus in 1833.
Theodor Schwann discovered that animals were made of cells in 1838. (chap:2,P.no:29-30)
Cell Theory
The Cell Theory states that:
All living things are composed of a cell or cells.
Cells are the basic unit of life.
All cells come from preexisting cells.(chap:2,P.no:30)
Cellular Organelles
The Plasma membrane
The boundary of the cell.
Composed of three distinct layers.
Two layers of fat and one layer of protein. (chap:2,P.no:34)
The Nucleus
The center of cellular activity.
Bordered by a porous membrane.
Contains thin fibers of DNA and protein called Chromatin.
Contains a small round nucleolus which produces ribosomes. (chap:2,P.no:35)
The Mitochondrion
It contains two membranes.
It’s the size of a bacterium.
Contains its own DNA.
Produces the high energy compound ATP. (chap:2,P.no:38)
The Chloroplast
Contains a double membrane.
The center section contains stacks of coin-like grana.
The Grana make up the thylakoid.
The grana is surrounded by a gel-like material called the stroma.
Found in plants and algae. (chap:2,P.no:38)
Ribosomes
Small non-membrane bound organelles.
They contain two sub units.
The center of protein synthesis.
They are either free floating or attached to the Endoplasmic Reticulum. (chap:2,P.no:39)
Endoplasmic Reticulum
A complex network of transport channels.
Two types: Smooth and Rough.
The smooth is ribosome free and functions in poison detoxification.
The rough contains ribosomes and releases newly made protein from the cell. (chap:2,P.no:37)
Golgi Apparatus
A series of flattened sacs that modifies, packages, stores, and transports materials out of the cell.
Works with the ribosomes and Endoplasmic Reticulum. (chap:2,P.no:37)
Lysosomes
A membrane bound organelle containing a variety of enzymes.
Their internal pH is 5.
They help digest food particles inside or out side the cell.
They are instrumental in recycling cellular debris.( first year)
The Vacuole
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Sacs that help in food digestion or helping the cell maintain its water balance.
Found mostly in plants and protists. (chap:2,P.no:39)
Cell Wall
Plants, algae, fungi, and bacteria contain an extra structure surrounding its plasma membrane.
It is called a cell wall.
Cellulose, Chitin, and peptidoglycan are the materials found in these cell walls. (chap:2,P.no:33)
Cell Types
Eukaryotic
Contains a nucleus and other membrane bound organelles.
Rod shaped chromosomes
Found in all kingdoms except the Eubacteria and Archaebacteria (chap:2,P.no:40)
Prokaryotic
Does not contain a nucleus or other membrane bound organelles.
One circular chromosome
Found only in the Eubacteria and Archaebacteria Kingdoms. (chap:2,P.no:40)
What are Viruses
A virus is a non-cellular particle made up of genetic material and protein that can invade living cells. (chap:4,P.no:87)
The Structure Of a Virus
Viruses are composed of a core of nucleic acid
The Nucleic acid core is surrounded by a protein coat called a capsid
The Nucleic core is either made up of DNA or RNA but never both. (chap:4,P.no:88)
Cyanobacteria
Photosynthetic bacterium
Bluish-greenish color
Contain membranes that carry out the process of photosynthesis
Do not contain the same type of chloroplasts as plants do
This bluish-greenish algae can be found nearly everywhere on earth.
Can survive in extremely hot environments and even extremely cold environment(chap:4,P.no:96)
Bacterium Shapes
Cocci~ Sphere shaped bacteria
Bacillus~ Rod shaped bacteria
Spirrillium ~ Spiral shaped bacteria
Flagella~ Leg-like structures that help to propel the bacterium. (chap:4,P.no:92)
Fungi:Fungal Characteristics
1)Cell wall made of Chitin
2)Heterotrophs and major Decomposers
3)Body is made of Long filaments of hyphae which form a mycelium
4)Reproduce sexually and asexually
Asexually by spores
Sexually by mating of hyphae filaments (chap:5,P.no:101)
Classification:-there are 1.5 billion species present in this world that’s why it is very difficult to study these species
without classification. Scientist(American Taxonomist)named R.H Whittaker in 1969 classified animals in to five
kingdoms(chap:3,P.no:78-79)
Kingdom prokaryote/monera:-include all unicellular prokaryotae, exam: bacteria and cynobacteria(chap:3,P.no:8283)
Kingdom protoctista/protista:-include all unicellular eukaryotae, exam: amoeba,paramecium and euglena
Kingdom fungi:-include all mullticellular, non chllorophyllus with thylocatic body called mycelium, exam: mushroom.
Kingdom plantae:-include all mullticellular, eukaryotic and chllorophyllus(autotroph), exam: apple, tree and crops.
Kingdom animalae:-include all mullticellular, eukaryotic and nonchllorophyllus(heterotrophy),exam: man,snake
hydra.
Units of classification:-(desending order)
Kingdom-phylum/division-class-order-family-genus-species(chap:3,P.no:80)
Bionomenclutare: As we already study above that to sudy organisms 1.5million that’s why every animal is given
a scientific(botanical) name which is based on the species(last name) and genus( first name), exam: Man=homo-sapies.
(chap:3,P.no:81-82)
 "THE BIG 4"MACROMOLECULES:-There are four classes of biological macromolecules: Proteins, lipids, carbohydrates
and nucleic acids.(All these topics are infirst year)
 Before you can understand the topics in this unit there are some key vocabulary terms you need to know
 Macromolecule:- A very large molecule, such as a polymer or protein, consisting of many smaller structural units
linked together. Also called supermolecule.
 Polymer:-manymolecule i.e:1glucose+2glucose+3glucose+4glucose+……………….nglucose=Carbohydrate
 Monomer:-singlemolecule i.e: now the basic unit of protien,carbohydrate,lipid isamino acid,glucose,fatty acid.
Note:- the three of macromolecule(protien,carbohydrate,fat) are present in food also in ur body but source is food.
Protien :-They are the major structural molecules in living things for growth and repair : muscles, ligaments,
tendons, bones, hair, skin, nails…IN FACT ALL CELL MEMBRANES have protein in them
• They make up antibodies in the immune system
• They make up enzymes for helping chemical reactions
• They makeup non-steriod hormones which
• THINK: Proteins= membranes, enzymes, antibodies, non-steriod hormones, structural molecules.
Fact:-organisms nail,hairs,thorn are made up of protien called kerotin.Aside from the protein found in animal
sources…protein can also be found in fruits, vegetables, grains, and nuts. Protien are made up of aminoacid(100A.A)
Lipid:- They are a great source of STORED ENERGY so we have it in the future.
• They INSULATE the body to maintain normal body temperature and they CUSHION the internal organs for protection.
• They produce hormones for the body called STERIODS
• They waterproof surfaces of animals,plants, and fruits- these are waxes!
• THINK: Waterproof, insulate, steriods, energy, cushion… “WISE C”
Fact:-In plants- in the seeds. In animals- in adipose tissue, connective tissue, in animal. Lipids make up the cell
membrane of all cells.
 Carbohydrate:- They are the main source for the body to gain energy. They are our fuel!
They make up the cell wall in plants which allow them to grow tall, without this carbohydrate, a plant would be a
mushy mess! This type of carbohydrate is called Cellulose.THINK:CARBS= ENERGY and CELL WALLS
Fact:- In plant foods- in the cell walls of plants --- in fruits, vegetables, peas, beans, SUGAR comes from a plant and so
does FLOUR! (pasta, potatoes, bread, candy, cookies). In animal products- in MILK.
 Nucleic acid:-The nucleic acids in food are not considered a substance that the body uses to gain energy. The types of
Nucleic Acids
• DNA (DeoxyriboNucleic Acid)
• RNA (RiboNucleic Acid)
 Photosynthesis: the process by which plant make their food from simple inorganic material to organic. (chap:9,P.no:154)
 parasite(ism):the symbiotic association in which one gets benefit and other is harmed. (chap:9,P.no:170)
 Nutrition:the study of organic substance(protien,carbo,fat) and getting energy. (chap:9,P.no:154-170)
 cell division: the process by which a cell reproduce and form identical like itself. (chap:2,P.no:41)
 Disease:
 Infection:the entery of germs inside the body.
 food chain:the transfer of food from producer to series of organisms.
 water cylce: the cycle by which water change from one form to another, from one place to another back to its orginal
position is called water cycle.
 stomata: the opening present on the surface of leaf through which the photosynthesis.
 sexual and asexual reproduction: the reproduction which include male and female both (sperm and ovary) is called
sexual reproduction while the reproduction which doesnot include male and female but only single cell is invovled is called
asexual reproduction.
 Locomotion: the process with the help of organ or organell by which an organism move.
 Feeding:when one organism eats other, this process is called feeding.
 Humus:when an organism is buried inside the earth for a long time its living material is converted into other form known
as humus
 Pollution(an silent destroyer): types of pollution: 1)water pollution 2)land pollution 3)air pollution
Important key point:(1)chromosome (2)Gene