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Mr. Wright, 2010
Section 19.1
Question 1:
How are they different?
Has no membrane
bound nucleus.
 Has no membrane
bound organelles
(chloroplasts,
mitochondria, etc.)
 Much simpler cells

Has a nucleus.

Contains membrane
bound organelles

Cells are more complex
than prokaryotic cells.
Prokaryotes
Eukaryotes

Question 2:
Prokaryotes make up two
domains:
TO CLARIFY – when people talk about
everyday bacteria, they are talking about
Eubacteria.
A bit about Archaea…
Archaeabacteria – “ancient bacteria”
 Have different cell walls than those seen
in other living organisms.
 Found in very extreme environments:

 Swamps
 Salt Lakes
 Deep Sea Vents
 Hot Springs
Archaea and You
What is global warming?
 Some archaea produce methane while
making energy and release this in to the
environment.

 Methane = greenhouse gas

Cows have a huge impact on global
warming. Why?
Question 3:
3 Bacterial Shapes:
…plus a little extra.

The prefix staph- means the cells are
grouped into clusters.

The prefix strept- means the cells are
arranged in chains.
Question 4:
A Typical Bacterial Cell:
What do these things do?

Genome
 Genetic Material (DNA) of the cell

Ribosomes
 Make proteins

Cytoplasm
 Fluid filling the inside of the cell
What do these things do?

Cell Membrane & Cell Wall
 Protects and supports the cell.

Flagella
 Used for movement

Pili
 Used to adhere to surfaces and other cells
Question #4:
Oxygen Requirements
Obligate anaerobes – cannot live where
there is oxygen
 Facultative anaerobes – can live with or
without oxygen
 Obligate aerobes – require oxygen to
live

Question 5:
Bacteria can be:

Photoautotrophs
 Get their energy from sunlight

Chemoautotrophs
 Get their energy from inorganic sources

Heterotrophs
 Get their energy from other organisms.
 MOST BACTERIA
Question 6
Binary Fission

Binary fission results in two daughter
cells that are exactly identical to the
mother cell.
Question 8:
Conjugation

Two bacterial cells
can join and
exchange genetic
information using
plasmids.
 “Prokaryotic sex”

Plasmid – smaller
circular molecules of
DNA in the
cytoplasm
Other methods:

Bacterial cells can take up DNA from the
environment (Transformation)
Other Methods:

Viruses can transfer new genetic
material into a bacterial cell.
(Transduction)
Question #9:
Endospores



Some bacteria can
form an endospore
when environmental
conditions become
harsh.
Can resist extreme
conditions.
When good conditions
return, the spores give
rise to normal
bacterial cells.
Question #10:
Nitrogen fixing bacteria
Almost 80% of Earth’s atmosphere is
made up of nitrogen gas, but plants and
animals cannot utilize it in this form.
 Nitrogen fixing bacteria convert this
nitrogen gas into a form that plants and
animals can use – nitrogen fixation

Bacteria in Industry
Bacteria provide many benefits to
humans, as well.
 We use bacteria to produce many
different types of foods.

 Yogurt
 Sour Cream
 Cheeses
Bacteria in Industry

Bacteria are also used to make certain
chemicals.
 Acetone
 Antibiotics
 Insulin

We use bacteria to help recycle and
break down organic wastes.
 Oil spills
 Sewage
Bacteria as art!
Section 19.3
Bacteria and Humans
Some bacteria cause disease in humans
by making toxins or by destroying tissue.
 Examples of bacterial diseases:

 Anthrax
 Lyme Disease
 Staph Infection
 Salmonella food poisoning
Germ Theory


Germ Theory was
the idea that illness
was caused by
bacteria.
Proven by Louis
Pasteur.
 Invented the first
vaccine.
 Made milk safer to
drink through
Pasteurization.
Antibiotics
Antibiotics kill bacteria by interfering with
cellular activities.
 Made naturally by fungi and other
bacteria to kill neighboring cells
competing for resources.

 Penicillin comes from a fungus.
Antibiotics – The Discovery

The first antibiotic (Penicillin) was
discovered by Alexander Fleming.
 It was an accident.
Fleming was working with bacteria in the
lab. One day, as he was heading home
for the weekend, he got lazy and left his
dishes out to clean on Monday.
 When he came back the next day, he
discovered Penicillium growing on his
plates… with no bacteria remaining.

Antibiotic resistance

Bacteria are evolving to become
resistant to antibiotics.
 A mutation giving resistance to the antibiotic.
 While the old strain is wiped out by
antibiotics, the new strand continues to
multiply and take over.
Reasons it’s a big problem:

Doctors overprescribe antibiotics when
they might not be completely necessary.

People “stockpile” extra antibiotics and use
them whenever they are sick.
Reasons it’s a big problem:

Bacteria that we used to have no
problem treating are becoming
untreatable… and it’s only getting
worse! 