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Bacteria
Chapter 7
Who discovered the world of
bacteria by observing scrapings from
his teeth using a simple microscope?
Antonie van Leeuwenhoek
One hundred years later, bacteria were
proven to be ________ ___________
that carry on all of the processes of life.
living cells
Where do bacteria live?
almost everywhere
Identify the three shapes of
bacteria and the name of each
shape.
Cocci – spherical
Bacilli – rod
Spirilla - spiral
Describe the structure of a bacterial cell.
Identify what a bacterial cell contains.
Cytoplasm, surrounded by a cell membrane and cell wall
Capsule – protects the bacterial cell and helps it stick to surfaces
Chromosome – contains genetic material
Ribosomes – make protein
Flagellum – enables the bacterium to move
Identify the two structures which
allow a bacterium to stick to
surfaces and also provide protection
for the bacterial cell.
Capsule
Slime layer
Many bacteria that live in moist
conditions have a ______, or whip-like
tail, to help them move.
flagella
By what process do most
bacteria reproduce?
Fission
Some bacteria exchange genetic information
through a process called ________________.
Exchanging genetic material helps the bacteria
acquire _______________ that make them better
suited for survival in a particular environment.
Conjugation
variation
Some bacteria make their own food
and are called _______. Others do
not make their own food and must
feed off other organisms. These
bacteria are called _____________.
Producers
Consumers
Most organisms use oxygen
when they break down food and
obtain energy through a process
called _____________
respiration
Bacteria that use oxygen for respiration
are called ________. Bacteria that are
adapted to live without oxygen are
called _________.
Aerobes
Anaerobes
Identify the two kingdoms of bacteria.
Contrast the two kingdoms.
•Archaebacteria
Live in extreme conditions
Consists of halophiles, themaphiles, and
methanogens
Oldest kingdom
•Eubacteria
Found in many environments but not extreme
Named based on shape, structure, how they
obtain food
Can cause disease
One important group of producer eubacteria is the
______________. They contain the pigment
____________ and make their own food. Their
common name is ____________. They live in lakes
and ponds and can form ______________ on top of
the water, which can be harmful to aquatic
organisms.
Cyanobacteria
Chlorophyll
Blue-green bacteria
bloom
What is one explanation of where
the Red Sea gets its name?
The Red Sea gets its name from the red
cyanobacteria which form on top of the water.
Explain how cyanobacteria can
be beneficial to ponds and lakes.
They are an important source of
food for some aquatic organisms.
Cyanobacteria, when too abundant, can form a
________ on top of the water. When cyanobacteria
use all of the available resources in the water they
_____. Other aerobic bacteria feed on the
cyanobacteria and use the oxygen in the water. As a
result of the reduced __________ and lack of
________, fish and other aquatic organisms die.
Bloom
Die
Food source
oxygen
Many consumer eubacteria are grouped into one of
two groups, Gram positive and Gram negative, based
on the results of the Gram’s stain. Explain the
difference in Gram positive and Gram negative
bacteria.
•Gram positive: stains purple because they
have thicker cell walls
•Gram negative: stains pink because they
thinner walls
One group of eubacteria is unique because they
do not produce ____ ______. This allows them
to change their shape. An example of this type of
bacteria is Mycoplasm pneumonia, a bacteria
that causes _____________.
Cell walls
pneumonia
Archaebacteria are bacteria that are
often found in extreme conditions.
Describe the following types of
archaebacteria.
•Halophiles: thrive in extremely salty
environments
•Thermaphiles: thrive in extremely
hot environments
•Methanogens: produce methane
gas; live in swamps, marshes, and in
the digestive tracts of cattle
Are most bacteria helpful or
harmful?
The benefits of most bacteria far
outweigh the harmful effects of a
few.
Bacteria in the digestive system helps
you __________ food and also produces
___________, which is important for
normal clotting of blood.
Digest
Vitamin K
Some bacteria produce chemicals called
__________ that limit the growth of some
bacteria. __________ produces the antibiotic
found in many nonprescription ________.
Antibiotics
Bacillus
ointments
Identify the bacteria which are
great recyclers. Explain how they
recycle.
Saprophytes
They use dead organisms as a food and
energy source and then recycle the
nutrients back into the environment for
other organisms to use
____________ are often used in
sewage treatment plants to
break down wastes into carbon
dioxide and water.
saprophytes
Explain how nitrogen–fixing
bacteria benefit plants.
Nitrogen-fixing bacteria change the nitrogen in
the air into a form that plants and animals can
use. Some plants have nodules on their roots in
which they store nitrogen-fixing bacteria.
What would happen to plants
without nitrogen-fixing bacteria?
Plants would have to be fertilized to get
the proper amounts of usable nitrogen.
Without it, the plants would die.
What is bioremediation?
Process that uses organisms to
help clean up or remove
environmental pollutants.
Identify five foods that are made
using bacteria.
Industries use bacteria to make many
products. Sometimes industries grow
bacteria in large containers called
_________.
bioreactors
Methane gas that is released as a
waste by certain bacteria can be
used for __________, _________,
and ______________.
Fuel for heating,
Cooking,
industry
Define pathogen.
Any organism that causes
disease
Identify two examples of
illnesses caused by pathogens.
Strep throat
Whooping cough
Tetanus
Anthrax
Some bacterial pathogens produce a
poisonous substance called a
__________. A type of food poisoning
caused by a toxin-producing bacterium is
___________.
Toxin
botulism
When growing conditions are
unfavorable for their survival, some
bacteria can produce endospores. What
are endospores?
Thick-walled structures
used for protection in
unfavorable conditions
such as high temperatures.
Unless it has been sterilized, all food
contains bacteria. Identify a process of
sterilization, and explain how it works.
Pasteurization: Process of heating food to a
temperature that kills most harmful bacteria
without changing the taste of the food.
__________ can be used to
prevent some bacterial diseases.
Vaccines
Explain how a vaccine is made.
A vaccine is made from damaged
cell walls or killed bacteria. Once
injected, white blood cells in the
blood recognize that type of
bacteria.
Bacterial diseases in humans and
animals are usually treated
effectively with _____________.
antibiotics
Why is botulism associated with
canned foods and not fresh
foods?
The bacteria which cause botulism are
anaerobes, which grow in an oxygen-free
environment such as than in canned foods.
The End!
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