BCLN BIOLOGY 11 – Rev July 2014
Unit 5 ~ Learning Guide
Name: _______________
INSTRUCTIONS
Using a pencil, complete the following notes and questions as you work through the
related lessons. You are required to have this package completed BEFORE you write
your unit test. Do your best and ask questions about anything that you don't understand
BEFORE you write the unit test.
5.1 NOTES: BACTERIAL CLASSIFICATION
Discovery of Bacteria
It
had
long
been
suspected
that
____________________________________________ which
are too small to be seen with naked eye. But
___________________________
________________________________________________
_____.
A
Dutch
scientist,
__________________________________________________
___ (1673), was the _________________________
___________________________________. He used
a simple microscope to describe bacteria and protozoa with
accurate drawings and descriptions and called these small
creatures animalcules. He first observed small creatures in
rain water, then confirmed these in saliva, vinegar, infusions and other substances.
The progress in understanding the nature and importance of these tiny organisms has
been slow. The existence of microbes was further confirmed by ___________________
_________________________________. Pasteur went on to make _______________
______________________________________________________________________
__________________________________________. His main achievements are the
development of vaccines for anthrax disease, fowl cholera and rabies. He also made
significant contributions in development of the pasteurization process and development
of fermentation industries. _____________________________________________
________________________________________________________________.
.
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BCLN BIOLOGY 11 – Rev July 2014
The Prokayotes
The Kingdom prokaryotae (often referred
to as _____________________) consists
of organisms with ___________________
_________________. Prokaryotic cells
_________________________________
_________________________________
_________________________________
______________ that typify the eukayota.
In Greek the word ___________________
____________________ _________ and
_________________________________
___________. Traditional classifications
have placed the archea and bacteria into
this single taxonomic kingdom due to their
morphological similarity. In fact the two
groups are extremely different, as different from each other biochemically as eukaryotes
are from either group. Microbiologists now recognize that there are
_____________________________________________________________: a much
smaller division called the Archaebacteria (Greek for _________________________________________
__________________________________________), a larger group called Eubacteria (Greek for _________
______________________), and the Eukaryotes.
Their small size, ability to rapidly reproduce (for example, the intestinal bacterium E. coli
can reproduce by binary fission every 15 minutes), and diverse habitats/modes of
existence make _________________________________________________________
______________________________________________________________. Bacteria
are wide spread in their occurrence. They are ________________________________
_____________________________________________________________________
____________________________________________________________________.
Their kind and number vary according to locality and environmental conditions. Some
bacteria are always present and contribute towards the natural flora. Others are present
in specific environments such as hot springs, alkaline/acidic soil, highly saline
environments, in highly polluted soils and waters.
Archaebacteria
The name comes from the root "archae" which means ancient. Archaebacteria are
considered among _______________________________________________________
__________________________________________________. The archeans are life's
extremists, occupying environments that "normal" organisms find too harsh such
__________________________________________________________. They do not
need oxygen or light to survive.
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BCLN BIOLOGY 11 – Rev July 2014
There are three groups of Archaea:
1. The _______________________________________ live under anaerobic
environments (e.g., marshes) where they produce methane.
2. _________________________________ require high salt concentrations (such
as in Utah's Great Salt Lake).
3. __________________________________ live under hot, acidic environments
(like those found in geysers)
Eubacteria
The Eubacteria and blue-green bacteria (once referred to as blue-green algae), or
cyanobacteria are the _________________________________________________
__________________________. The name comes from the root "eu" which translates
as ____________________. They are the most common forms of bacteria. There are
approximately 12 different phyla. ___________________________________________
_____________________________________________________________________.
.
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BCLN BIOLOGY 11 – Rev July 2014
Classifying Bacteria
Bacteria can are classified by a number of different criteria:
Most bacteria come in one of three different shapes. Some bacteria tend to organize
into groups.
Term Describing
Bacterial Shape
Picture of Bacterial
Shape
Prefix Describing
Bacterial Arrangement
1. _______________ =
_______________
1. _______________ =
_______________
e.g. diplococci are pairs
of spherical shaped
bacteria
2. _______________ =
_______________
2. _______________ =
_______________
e.g. streptococci are
chains
of
spherical
shaped bacteria
3. _______________ =
_______________
3. _______________ =
_______________
e.g. staphylococci are
clusters of spherical
shaped bacteria
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Picture of Bacterial
Arrangement
BCLN BIOLOGY 11 – Rev July 2014
Classifying Bacteria by Staining
The _______________________________ is the most important staining procedure in
microbiology. It is _______________________________________________________
______________________________________________________________________
_________________________________. Hence, it is a differential stain.
Gram staining involves a four-part process, which includes:
1. crystal violet
2. the primary stain iodine
3. the mordant a decolourizer made of acetone
4. alcohol safranin, the counterstain.
Gram negative and gram positive organisms are distinguished from each other
________________________________________________________________. These
differences affect many aspects of the cell, including the way the cell takes up and
retains stains.
____________________________________________
__________________, which is then fixed in the cell
with the iodine mordant. This forms a crystal-violet
iodine complex which remains in the cell even after
decolorizing. It is thought that this happens because the
cell walls of gram positive organisms include a
_____________________________
protein-sugar
complexes called __________________________.
This layer makes up 60-90% of the gram positive cell
wall. Decolorizing the cell causes this thick cell wall to dehydrate and shrink, which
closes the pores in the cell wall and prevents the stain from exiting the cell. At the end of
the gram staining procedure, ______________________________________________
______________________________________________________________________
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BCLN BIOLOGY 11 – Rev July 2014
Gram negative cells also take up crystal violet, and the iodine forms a crystal violetiodine complex in the cells as it did in the gram positive cells. However, ___________
_________________________________________________________________
____________________________________________________. Peptidoglycans
are present in the cell walls of gram negative organisms, but they only comprise 10-20%
of the cell wall. Gram negative cells also have an outer layer which gram positive
organisms do not have; this layer is made up of lipids, polysaccharides, and proteins.
Exposing gram negative cells to the decolourizer dissolves the lipids in the cell walls,
which allows the crystal violet-iodine complex to leach out of the cells. This allows the
cells to subsequently be stained with safranin.________________________________
_____________________________________________________________________
____________________________________________________________________.
Classifying Bacteria by Nutrition
Bacteria are classified on the basis of their method of ____________________
______________________. Traditional classifications include ___________________
___________________________________________________________________
___________________________________________________________________
____________________________________ groups.
1. Chemosynthetic Bacteria - __________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
 Example: Pseudomonas aeruginosa
2. Photosynthetic Bacteria - ____________________________________________
________________________________________________________________.
Cyanobacteria are the major group of photosynthetic bacteria. Some early
cyanobacteria may have formed the ___________________________________
________________________________, transforming our planet from one with
an oxygen-free atmosphere, to the modern one that has a significant amount of
oxygen present.
 Example: Heliobacteria from soil.
3. Saprophytic bacteria are heterotrophic bacteria that ______________________
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________
.
4. Parasitic bacteria are heterotrophic bacteria that _________________________
_______________________________________________________________.
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BCLN BIOLOGY 11 – Rev July 2014
5. Other Bacteria are classified as ____________________________.
Decomposers
play
an
important
role
in
nature
as
they
__________________________________. They are an important part of the
food chain.
In summary, bacteria use all modes of nutrition. Some bacteria are autotrophic (able to
produce their own energy) by photosynthesis and others by chemosynthesis. Most types
of bacteria however, are heterotrophic by absorption. __________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________ .
Others absorb nutrients from other living things and are known as parasites.
5.1 PRACTICE: BACTERIAL CLASSIFICATION
1. Recent classification schemes have determined there are three domains of life:
a. What are these domains called? (3 marks)
b. Which if these domains contain bacteria? (2 marks)
2. What distinguishes the domains that contain bacteria from the one that does
not? Hint: think cellular structure. (2 marks)
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BCLN BIOLOGY 11 – Rev July 2014
3. Please classify each of the following bacteria using the terms gram positive,
gram negative, staphylo-, strepto-, diplo-, -cocci, -bacilli, -spirilli. (12 marks)
Shape/Organization
Gram Stain
Classification
Colour
Example: gram negative, monospirillum
pink
*note: mono = one = individual bacteria
purple
purple
pink
pink
4. A gram positive bacteria is likely to have a great deal more
_____________________________________________ in its cell wall than a
gram negative bacteria and thus, it will bind to and retain the Gram stain better.
(1 mark)
5. Chemosynthetic bacteria are said to be ________________________ because
they can produce energy and organic compounds for themselves, whereas most
other bacteria are ____________________________ as they obtain energy and
organic compounds by feeding off of other living things. (2 marks)
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BCLN BIOLOGY 11 – Rev July 2014
5.2 NOTES: BACTERIAL STRUCTURE
__________________________________
______________________________ - but
don't let their small size and seeming
simplicity fool you. They are an amazingly
complex and fascinating group of
organisms. Bacteria, since they are
prokaryotes, _______________________
__________________________________
__________________________________
__________________________________
that normally occur in a chloroplast or
mitochondrion of eukaryotes will _______
_________________________________
________________________________.
Bacterial __________________________
_______________ and arrayed in a region
of the cell known as the ______________.
Scattered within bacterial cytoplasm are
numerous _________________________
__________________________________
___________ which are often used to
carry foreign DNA into other bacteria for recombinant DNA engineering. The
________________________________________________________, the structures
where proteins are assembled. All bacteria also have a _________________________
_______________________________, which is usually surrounded by a __________
_______________________________________________.
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BCLN BIOLOGY 11 – Rev July 2014
Bacterial Structure
Associated Function
plasmid
_____________________________
capsule
________________________________________________ made up of
polysaccharides (complex sugars. _________________________
______________________________________ and protects it from
drying out
cell wall
gives
cell
its
shape
and
surrounds
the
cytoplasm
_________________________________________________________
plasma membrane
a layer of phospholipids and proteins that allows certain materials into
and out of the cell
ribosome
Only type of cell organelle found in bacteria. Small factories that
translate the genetic code into proteins.
fimbriae
Small hair-like projections that emerge from the cell membrane.
_________________________________________________________
____________________________________________
cytoplasm
Or protoplasm, this is where the functions of cell growth, cellular
metabolism and replication are carried out. It is a gel-like material that is
composed of water, enzymes, nutrients, wastes and gasses and cell
structures such as the ribosomes, chromosomes, and plasmids.
nucleoid
A region of the cytoplasm where the chromosomal DNA is located
flagella
Hair-like structures that ___________________________________. Not
all bacteria have flagella.
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BCLN BIOLOGY 11 – Rev July 2014
Endospores
Bacteria = _______________________________
________________________________________
Microorganisms sense and adapt to changes in
their environment. When favored nutrients are
exhausted, some bacteria may become motile to
seek out nutrients, or they may produce enzymes
to exploit alternative resources. _______________
________________________________________
________________________________________
________________________________________.
This complex developmental process is ______________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
_____________________________________________________________________.
Endospores can survive environmental assaults that would normally kill the bacterium.
These stresses include ___________________________________________________
_________________________________________________________________. The
extraordinary resistance properties of endospores make them of particular importance
because they are not readily killed by many antimicrobial treatments. A variety of
different microorganisms form spores or cysts, but the endospores of bacteria are by far
the most resistant to harsh conditions.
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BCLN BIOLOGY 11 – Rev July 2014
5.2 PRACTICE: BACTERIAL STRUCTURE
1. Please draw a simplified diagram of a bacteria cell being sure to include and
label the structures listed below. Please include a brief description of the
structure's function beside the label. Please be neat. (10 marks)
o nucleoid
o plasmid
o cytoplasm
o cell wall
o fimbriae
o ribosomes
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o flagella
o capsule
o plasma
membrane
BCLN BIOLOGY 11 – Rev July 2014
5.3 NOTES: BACTERIAL REPRODUCTION
Binary Fission
________________________ is the
____________________________
____________________________
by division into two approximately
equal parts. This method of cellular
reproduction
occurs
only
in
prokaryotes
(bacteria
and
archaeans).
As one might expect, the volume of
the two daughter cells produced is
initially half that of the parent cell
before the division. But each
daughter cell does contain a
complete copy of the parental
chromosome.
Before fission can occur, ________
____________________________
____________________________,
which is circular. Each chromosome
then affixes itself to the cell
membrane. As the cell stretches out during division, the two chromosomes move apart,
and one passes into each of the two daughter cells.
The actual physical division of the cell into two compartments occurs when __________
______________________________________________________________________
_______________________________________ across the middle of the cell.
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BCLN BIOLOGY 11 – Rev July 2014
Exchange of Genetic Information
______________________________________________________________________
___________________________________. When bacteria exchange DNA it has a
similar effect to ____________________________ as there is a _________________.
___________________________________________________________. There are
three ways in which bacteria exchange DNA.
1. __________________________ - male cell passes
DNA to the female cell by means of a conjugation tube
i.e., sex pilus.
2. _________________________
DNA released by dead bacteria.
- bacterium takes up
3. ______________________________ - bacteriophages
carry DNA from one cell to another
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BCLN BIOLOGY 11 – Rev July 2014
5.3 PRACTICE: BACTERIAL REPRODUCTION
1. Please identify which process in being represented by each picture below
(transduction, binary fission, conjugation, and transformation) and then provide a
brief description of the process in the box beside the picture. (8 marks)
Various Processes that Affect the Genetic
Composition of Bacteria
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BCLN BIOLOGY 11 – Rev July 2014
5.4 NOTES: BACTERIAL METABOLISM
The diversity of prokaryotes is expressed by their _____________________________
__________________________________________________________________ ,
and this feature allows prokaryotes to flourish in all habitats on earth. Bacteria have
been found that can live at ____________________________________________
and in those that would ______________________________________. They "eat"
______________________________________________________________________
____________________________________. There is even a species of bacteria that
can withstand blasts of radiation 1,000 times greater than those that would kill a human
being.
Most bacteria are __________________________________________. These bacteria
____________________________________________________. These bacteria utilize
cellular respiration to produce energy. Cellular Respiration is the breakdown of sugar
molecules with the use of oxygen to release energy.
C6H12O6 + 6O2 --------> 6 H2O + 6 CO2 + Energy
Some bacteria are called ________________________________________________
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
a. Photosynthesis is __________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________

Cyanobacteria is an example of a photosynthetic bacteria.
6 CO2+ 6 H2O -----light------>C6H12O6 + 6 O2
b. ________________________________________________________________
________________________________________________________________
________________________________________________________________
______________. Fermentation is _____________________________________
_______________________________________________. Bacteria will ferment
by one of these two equations.

Pyruvic Acid + NADH ---------->Lactic Acid + NAD+ (also used by animals)

Pyruvic Acid + NADH ---------->Alcohol + CO2 + NAD+ (also used by
plants)
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BCLN BIOLOGY 11 – Rev July 2014
Other bacteria are ____________________________________. Facultative anaerobes
are ___________________________________________________________________
___________________________. These bacteria will use cellular respiration if oxygen
is present and fermentation if oxygen is not present.
Beneficial Bacteria
Bacteria provide us with products which we depend every day. For example, bacteria
. Some bacteria are used to make pickles and sauerkraut, and some make
vinegar from wine.
Bacteria are also used in industry. One type of bacteria can digest petroleum, which
makes them _______________________________________________________.
Some bacteria remove waste products and poisons from water. These bacteria can be
____________________________________________________________. Others can
even ___________________________________________________ from the ground.
Still others have been __________________________________________________
and chemicals through techniques of genetic engineering.
Many kinds of bacteria develop a symbiotic relationship with other organisms in which
______________________________________. Our intestines are inhabited by large
numbers of bacteria including E. coli. In the intestines, the _______________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
_____________________________________________________________________.
Bacteria _______________________________________________________________
_______________________________. Gradually, the material being decomposed is
recycled, enriching the soil thereby providing valuable nutrients required for plant
growth.
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BCLN BIOLOGY 11 – Rev July 2014
5.4 PRACTICE: BACTERIAL METABOLISM
1. Please compare and contrast the terms obligate anaerobe and obligate aerobe.
(3 marks)
2. Would it technically be incorrect to refer to a facultative anaerobe as a facultative
aerobe? Please explain your answer? (2 marks)
3. Tired of always being portrayed as the "bad guys" (see image below), a group of
bacteria have hired you as their new public relations (PR) representative. Please
design a PR device to improve the image of bacteria in the eyes of the human
population. You may design a poster, radio commercial (script), TV commercial
(post on YouTube), song (send lyrics or post on YouTube), comic strip, children's
colouring pages or any other device that you think will help to inform the public of
some of the benefits of bacteria. (10 marks)
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BCLN BIOLOGY 11 – Rev July 2014
5.5 NOTES: BACTERIAL DISEASE
Symbiosis in Bacteria
When bacteria live in association with other organisms they are known as
___________________________________________. There are ________________
____________________________, and different groups of bacteria employ all three.
1. In ___________________________ (+/+) symbiotic relationships, ___________
__________________________________________ from the relationship. For
example, nitrogen fixing bacteria live in nodules of legumes. They provide the
plant with nitrogen and the plant supplies the bacteria with other nutrients.
2. In a __________________________ (+/0) relationship, ____________________
_______________________________________________________________.
Bacteria live on human skin and do not harm us, but benefit from the warm moist
environment.
3. A _____________________________ (+/-) relationship means that __________
________________________________________________________________
__________________________________. Parasitic bacteria harm the host and
___________________________________________________. Some parasitic
bacteria use a human host, so the study of bacteria is of great importance to
human beings.
Most bacteria however are not pathogenic. Useful bacteria include:
 decomposers
 nitrogen fixing bacteria
 vitamin producing bacteria
 bacteria used to make insulin (E.coli) and growth hormones
 Some bacteria are used to make antibiotics (e.g. Streptomycin)
There are many industrial bacteria. Such as bacteria ___________________________
_____________________________________________________________________.
Bacteria __________________________________________________________
________________________________________________________ . Scientists
use bacteria in genetic research because they only have 1 chromosome, are easy to
grow, and have a short life cycle
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BCLN BIOLOGY 11 – Rev July 2014
Harmful Bacteria and Koch Postulates
As stated previously most bacteria are _____________________ which means they are
________________________________. Many actually help us in some way (digestion,
protection). There are relatively few bacteria that are considered to be pathogenic or
disease causing. Pathogenic or disease causing bacteria ________________________
______________________________________________________________________
__________________________. Bacteria may produce endotoxins and exotoxins
which elicit an immune response.
Koch’s Postulates
________________________
was a German Bacteriologist
who came up with the rules to
prove that an organism is
responsible for a particular
condition or disease. He
formulated the "germ theory
of disease". He isolated
typical rod-shaped bacteria
with squarish ends (bacilli)
from the blood of sheep that
had died of anthrax. Then he
Discovered
bacteria
that
caused
tuberculosis
and
cholera. Robert Koch ____________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
1. A specific organism can always be found in association with a given disease.
2. ________________________________________________________________
________________________________________________________________
3. The pure culture will produce the disease when inoculated into susceptible
animal.
4. ________________________________________________________________
________________________________________________________________
________________________________________________________________
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BCLN BIOLOGY 11 – Rev July 2014
Koch and his colleagues invented many techniques concerning inoculation, isolation,
media preparation, maintenance of pure cultures and preparation of specimens for
microscopic examination.
Examples of Bacterial Disease
1. ______________________________________________:
 Strept throat
 Rheumatic Fever
 Pneumonia
 Tuberculosis
2. _____________________________________________:
 Staph
 Pimples
 Leprosy
 flesh eating disease
3. _____________________________________________:
 tetanus
 Botulism
 meningitis
4. _____________________________________________:
 Typhoid fever
 cholera,
 Salmonella
 E. coli
5. _____________________________________________:
 Gonorrhea
 Syphilis
Lines of Defense
The human body constantly faces attack from foreign invaders that can cause infection
and disease. These invaders range from living microbes such as bacteria, fungi, and
viruses, to nonliving toxins, chemicals, and drugs. Fortunately, the body has a number
of external and internal safeguards that prevent most dangerous invaders from entering
and causing harm.
The ______________________________________________ is non–specific and aims
to stop microbes from entering the body. The ________________________________
__________________________________________________________ preventing
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BCLN BIOLOGY 11 – Rev July 2014
penetration by microbes. If the skin is cut then the blood produces a ______________
__________________________________________________________________
_________________________. The surfaces of the body – the skin, digestive system,
and the lining of the nose – are covered by a _______________________________
________________________ called the normal body flora. They help to protect a host
from becoming infected with more harmful micro-organisms by acting as a physical
barrier. It means that the harmful microbes have to compete with the normal body flora
for nutrients. The average human gut contains around 1 kg of these good bacteria which
is equivalent to one bag of sugar. The respiratory system – the nose and passageways
leading to the lungs – is lined with cells that produce sticky fluid called _____________
____________________________________________________, where they are
either coughed or sneezed out or swallowed and then passed out of the body in feces.
The body produces several antimicrobial substances that kill or stop microbes from
growing. For example the _______________________________________________
____________________________________. The ____________________________
_____________________________ which destroys many of the microbes that enter
the body in food and drink. Urine as it flows through the urinary system flushes microbes
out of the bladder and urethra.
If microbes do manage to get inside the body then the _________________________
_____________________________ is activated. This is also non-specific as it stops
any type of microbe. ___________________________________________________
__________________________________________________________. They send
out pseudopodia which allows them to _____________________________________
_________________________________________________. Phagocytes release
digestive enzymes which break down the trapped microbes before they can do any
harm. This process is called phagocytosis.
The __________________________________________________________________
_____________________________________________________________________
_________________________________________________________________. It is
regarded as a threat by the immune system and is capable of stimulating an immune
response. Antigens are proteins that are found on the surface of the pathogen. Antigens
are unique to that pathogen. The whooping cough bacterium, for example, will have
different antigens on its surface from the TB bacterium. When an antigen enters the
body, ________________________________________________________________
against it. It is like a battle with the army (antibody) fighting off the invader (antigen). A
type of white blood cell called ___________________________________________
______________________________________________________________________
_____________________________________________________. Each antibody has
a unique binding site shape which locks onto the specific shape of the antigen. The
antibodies destroy the antigen (pathogen) which is then engulfed and digested by
macrophages.
Once the invading microbes have been destroyed the immune response winds down.
Once a person has had a disease they don‘t normally catch it again because
the body produces __________________________________________________
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BCLN BIOLOGY 11 – Rev July 2014
_________________________________. The memory cells remember the microbe
which caused the disease and ___________________________________________
_________________________________________________________. The pathogen
is quickly destroyed preventing symptoms of the disease reoccurring.
What are Antibiotics?
Antibiotics are _________________________________________________________
_____________________________________________________________. The first
antibiotic was discovered by ______________________________________________
in 1928 in a significant breakthrough for medical science. The development of antibiotics
is probably the largest advance in medicine in the 20th century, and has saved millions
of lives worldwide from infections such as TB.
Since ________________________________________________________________
_______________________________, a wide range of antibiotics has been developed.
Originally produced from molds and fungi, many antibiotics are now produced
synthetically. Antibiotics are not effective against infections caused by viruses, so if you
go to your doctor with a viral illness such as a cold, flu or a viral sore throat, antibiotics
have no role to play. ____________________________________________________
_________________________________________________. For example, if you have
a streptococcal throat, penicillin may be prescribed. __________________________
_______________________________________________________. These are called
broad _________________________________________. This type of antibiotic is often
used to treat respiratory or urinary tract infections because it is difficult to establish what
specific bacteria are causing the condition.
Antibiotics can be classified into five main categories:
1. PENICILLINS including: Amoxycillin, Amoxil, Augmentin, Calvepen, Clonamox,
Floxapen
2. CEPHALOSPORINS including: Cefodox, Distaclor, Keflex, Suprax, Zinnat
3. AMINOGLYCOSIDES including: Genticin
4. TETRACYCLINES including: Clinimycin, Hostacycline, Minocin, Vibramycin
5. OTHERS including: Ciproxin, Erymax, Erythrocin, Flagyl, Ipral, Klacid, Zithromax
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BCLN BIOLOGY 11 – Rev July 2014
The choice of antibiotic depends on the _____________________________________
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
How do antibiotics work?
An antibiotic is a selective poison. It has been chosen so that it will ________________
______________________________________________________________________.
Each different type of antibiotic affects different bacteria in different ways. Essentially,
antibiotic drugs _________________________________________________________
________________________________________, allowing the body‘s immune
system to deal with the infection. For example, an antibiotic might inhibit a bacterium's
ability to turn glucose into energy, or its ability to construct its cell wall. The most
commonly used antibiotics, penicillins and cephalosporins, are bactericidal and work by
____________________________________________________________. When this
happens, the bacterium dies instead of reproducing.
Considerations for the use of antibiotics:




The antibiotic _____________________________________________________.
Some people are ____________________________________________.
Some antibiotics could kill off useful bacteria. ____________________________
________________________________________________________________
________________________________________________________________.
May cause resistant strains to develop.
Other biocides
disinfectants.
include:
Sulfur
Drugs,
antitoxins,
Chart of various antibiotics:
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various bacteriocides,
BCLN BIOLOGY 11 – Rev July 2014
Antibiotic Resistance
Antibiotics kill or inhibit the growth of susceptible bacteria. Many diseases that once
killed people can now be treated effectively with antibiotics. An antibiotic is a _________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
_____________________________________________________________________.
Sometimes one of the bacteria survives because it has the _____________________
_______________________________________________________;
that
one
bacteria can then _______________________________________________________
______________________________________. Exposure to antibiotics therefore
provides selective pressure, which makes the surviving bacteria _________________
___________________________________________. In addition, bacteria that were
at one time susceptible to an antibiotic can ___________________________________
through _________________________________ of their genetic material or by
acquiring pieces of DNA that code for the resistance properties from other bacteria.
Although bacteria are capable of developing ___________________________________
______________________________________________________________________
a number of factors may speed up the development of resistance. These include:
1. ________________________________________________________________
_______________________________________________________ in humans.
2. Widespread use of antibiotics in the rearing ______________________________
________________________________________________________________
3. _________________________________________________________________
_____________________________ as prescribed by your doctor.
The danger of widespread resistance to antibiotics is that ______________________
__________________________________________________________ (so-called
'superbugs'). There is huge concern among doctors that eventually these 'superbugs'
could cause untreatable infections in the otherwise healthy populations. Most infectioncausing bacteria can become resistant to at least some antibiotics. Bacteria that are
resistant to many antibiotics are known as multi-resistant organisms (MROs).
How can it be prevented?
1. _________________________________________________________________
_________________________ like a cold or the flu.
2. Discard any leftover medication once you have completed your prescribed course
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BCLN BIOLOGY 11 – Rev July 2014
of treatment.
3. ________________________________________________________________
_________________________________________________. Complete the
prescribed course of treatment even if you are feeling better.
4. Do not take antibiotics prescribed for someone else.
5. Stop the use of antibacterial hand soaps and sanitizers. Wash your hands with
regular soap and water instead.
This first bacterial streak plate shows the effect of
antibiotic disks on bacteria. There is no growth near the
white disks.
On this second streak plate the bacteria now exhibit
resistance to the antibiotic disks.
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BCLN BIOLOGY 11 – Rev July 2014
5.5 PRACTICE: BACTERIAL DISEASE
1. The human body has three lines of defense against pathogens (disease-causing
agents):
a. Please identify and briefly describe the first line of defenses. (2 marks)
b. Please identify and briefly describe the second line of defenses. (2 marks)
c. Please identify and briefly describe the third line of defenses. (2 marks)
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BCLN BIOLOGY 11 – Rev July 2014
2. You often hear people express concern that if they use antibiotics inappropriately
that "they will become resistant to the antibiotic". While a person is correct in
being concerned about the inappropriate use of antibiotics, this particular
statement reflects a severe misconception of what "antibiotics resistance" is.
What does antibiotics resistance refer to and how does the inappropriate use of
antibiotics contribute to its existence? Please include terms such as mutation,
selective pressure/natural selection, survival of the fittest and next generation in
your answer. (5 marks)
~ END OF BIOLOGY 11 UNIT 5 LEARNING GUIDE ~
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BCLN BIOLOGY 11 – Rev July 2014
UNIT 5 ANSWER KEY
5.1 PRACTICE: BACTERIAL CLASSIFICATION
1. Recent classification schemes have determined there are three domains of life:
a. What are these domains called? (3 marks)
Archaea, Bacteria, Eukaryota
b. Which if these domains contain bacteria? (2 marks)
Archaea and Bacteria
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BCLN BIOLOGY 11 – Rev July 2014
2. What distinguishes the domains that contain bacteria from the one that does not? Hint: think
cellular structure. (2 marks)
The domains that contain bacteria (Archaea and Bacteria) includes only prokaryotic
cells that lack a nucleus and other membrane-bound organelles. In contrast, the
domain that does not contain bacteria (Eukaryota) includes only eukaryotic cells
that generally have a nucleus and other membrane-bound organelles.
3. Please classify each of the following bacteria using the terms gram positive, gram negative,
staphylo-, strepto-, diplo-, -cocci, -bacilli, -spirilli. (12 marks)
Shape/Organization
Gram Stain
Classification
Colour
Example: gram negative, monospirillum
pink
*note: mono = one = individual bacteria
gram positive streptobacilli
purple
gram positive staphylococci
purple
gram negative staphylobacilli
pink
Gram negative streptococci
pink
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BCLN BIOLOGY 11 – Rev July 2014
4. A
gram
positive
bacteria
is
likely
to
have
a
great
deal
more
_____________________________________________ in its cell wall than a gram negative
bacteria and thus, it will bind to and retain the Gram stain better. (1 mark)
5. Chemosynthetic bacteria are said to be ________________________ because they can
produce energy and organic compounds for themselves, whereas most other bacteria are
____________________________ as they obtain energy and organic compounds by feeding off
of other living things. (2 marks)
5.2 PRACTICE: BACTERIAL STRUCTURE
2. Please draw a simplified diagram of a bacteria cell being sure to include and label the
structures listed below. Please include a brief description of the structure's function beside
the label. Please be neat. (10 marks)
o nucleoid
o plasmid
o cytoplasm
o cell wall
o fimbriae
o ribosomes
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o flagella
o capsule
o plasma
membrane
BCLN BIOLOGY 11 – Rev July 2014
5.3 PRACTICE: BACTERIAL REPRODUCTION
1. Please identify which process in being represented by each picture below (transduction, binary
fission, conjugation, and transformation) and then provide a brief description of the process in the
box beside the picture. (8 marks)
Various Processes that Affect the Genetic
Composition of Bacteria
Binary Fission - genetic material replicated then cell divides into two identical
(barring mutation) daughter cells
Transduction - viral vector carries genetic material from one bacteria to
another during the process of infection
Transformation - bacteria picks up random genetic material from its
environment
Conjugation - plasmid (genetic material) is transferred from one bacterial cell
to another via a conjugation bridge formed by a pilus/fibriae
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BCLN BIOLOGY 11 – Rev July 2014
5.4 PRACTICE: BACTERIAL METABOLISM
1. Please compare and contrast the terms obligate anaerobe and obligate aerobe. (3 marks)
Obligate means "required" or "restricted to"…an obligate anaerobe must metabolize
and live without oxygen whereas an obligate aerobe must metabolize and live with
oxygen.
2. Would it technically be incorrect to refer to a facultative anaerobe as a facultative aerobe?
Please explain your answer? (2 marks)
Facultative means it can occur optionally but is not restricted to a particular
condition or environment. A facultative anaerobe can function in the absence or
presence of oxygen. Likewise, a facultative aerobe can function in the presence or
absence of oxygen. Thus, the terms can be correctly used interchangeably.
3. Tired of always being portrayed as the "bad guys" (see image below), a group of bacteria have
hired you as their new public relations (PR) representative. Please design a PR device to
improve the image of bacteria in the eyes of the human population. You may design a poster,
radio commercial (script), TV commercial (post on YouTube), song (send lyrics or post on
YouTube), comic strip, children's colouring pages or any other device that you think will help to
inform the public of some of the benefits of bacteria. (10 marks)
Approachesand answers may vary but may include pointing out the benefits of
bacteria such as:
o
Commensal bacteria preventing colonization of human body by harmful
bacteria
o
Commensal bacteria helping in digestion and vitamin production
o
Use in food manufacture such as yogurt, cheese, sour cream, vinegar, and
pickles
o
Use in bioremediation of oil spills and mining sites
o
Use in recycling/decomposition of dead matter and nitrogen-fixation.
o
Use in scientific research.
o
Use in production of insulin, human growth hormone and Factor VIII for
use in human medicine.
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BCLN BIOLOGY 11 – Rev July 2014
5.5 PRACTICE: BACTERIAL DISEASE
1. The human body has three lines of defense against pathogens (disease-causing agents):
a. Please identify and briefly describe the first line of defenses. (2 marks)
Non-specific barriers including:
o
Physical – skin and mucus
o
Chemical – tears and saliva, stomach acid
b. Please identify and briefly describe the second line of defenses. (2 marks)
Non-specific including:
o
Cells – phagocytes
c. Please identify and briefly describe the third line of defenses. (2 marks)
Specific including:
o
T and B Cells – that work together to destroy specific
pathogens using antibodies produced by B cells
2. You often hear people express concern that if they use antibiotics inappropriately that "they will
become resistant to the antibiotic". While a person is correct in being concerned about the
inappropriate use of antibiotics, this particular statement reflects a severe misconception of what
"antibiotics resistance" is. What does antibiotics resistance refer to and how does the
inappropriate use of antibiotics contribute to its existence? Please include terms such as
mutation, selective pressure/natural selection, survival of the fittest and next generation in your
answer. (5 marks)
Answers should include the following key points:
o
Antibiotic resistance refers to a strain of bacteria being resistant (not
significantly harmed or controlled by) an antibiotic not to a human being
resistant to the antibiotic.
Indeed, humans should be resistant to all
antibiotics or else their use would kill our cells and therefore, us.
o
Bacteria become resistant to an antibiotic through random mutation. This
makes them more "fit" in scenarios where an antibiotic is being used.
o
When antibiotics are used inappropriately (not taken for the full
recommended course) or excessively we are essentially selecting for the
naturally occurring resistant mutants.
o
We kill off the non-resistant bacteria and all that are left are the stronger
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BCLN BIOLOGY 11 – Rev July 2014
more resistant bacteria.
o
These bacteria now have less competition and can rapidly reproduce and take
over the organism they are infecting.
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