Transcript bacteria, viruses, and cells

Bacteria, Viruses,
and Cells
Bacteria, Viruses,
and Cells
We are going to discuss the similarities and differences in Bacteria, Viruses,
and Cells
By the end of the lesson you should be able to explain:
•Whether or not they are alive and how we can tell
•How they Reproduce
•What type of genetic material they contain
•And give some examples of each
Bacteria
Cells
Viruses
Basics
Bacteria
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Prokaryotes
Can be beneficial
or harmful
No internal
compartments or
membrane
systems
They are single
celled
Three basic
shapes
 Bacillus –rod
 Coccus –
round
 Spirillum –
spiral
Antibiotics do kill
them
Cells
■ Eukaryotes or
Viruses
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Prokaryotes
■ Have
organelles
■ Many different
types and they
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can be
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specialized
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Segments of
Nucleic Acids
contained in a
protein coat
(capsid)
 Some have an
envelope
around the
capsid
Not prokaryote or
eukaryote
Much Smaller than
Bacteria and Cells
Variety of shapes
Antibiotics do not
kill them
Only harmful
Are they alive and How do we know?
Bacteria
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Bacteria Are
ALIVE
They can
metabolize food
They do contain
Ribsomes to
make proteins
They can
reproduce
without a host
cell
Cells
■ Cells are ALIVE
■ They can
metabolize
food
■ They do contain
ribosomes to
make proteins
■ They can
reproduce
without a host
cell
■ Interact with
their
surroundings
Viruses
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Viruses are NOT
ALIVE
They cannot
metabolize food
They have no
structures to
make proteins
(ribosomes)
They cannot
reproduce
without a host
cell
How do they Reproduce?
Bacteria
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Bacteria
reproduce by a
process called
Binary Fission
Cells
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Cells reproduce
Mitosis – for most
cells
Meiosis - for
gamete cells
Viruses
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Viruses have 2
possible ways of
reproducing
Lytic Cycle
Lysogenic Cycle
What Type of Genetic Material Do They Have?
Bacteria
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DNA and RNA
DNA is found in
the cytoplasm
because
Bacteria have no
nucleus
Round DNA
Cells
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DNA and RNA
Found in the
nucleus
Linear DNA
Viruses
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DNA OR RNA, but
not both
How are they transmitted?
Bacteria
Viruses
Bacteria and viruses are transmitted in much the same way
Inhalation
 Direct Contact
 Contact with Body Fluids (Blood,
Saliva, semen)
 Contaminated food or water
 Bite of an infected animal or insect

Examples
Bacteria
Cells
Viruses

Cholera

Muscle cells

AIDS
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Dental Cavities
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Nerve Cells
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Common Cold
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Strep Throat
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Guard Cells
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Flu
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Tetanus
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Rabies
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Used in
making food
and beverages
Mycorrhizae

Hepatitis

Smallpox

TAKS Question
Which of the following is found in both cells
and viruses?
 A Silica
 B Genetic material
 C Digestive cavity
 D Flagella
TAKS Question
Viruses differ from bacteria in that all viruses
—
 F cause insect-borne diseases
 G can be destroyed by antibiotics
 H have rigid cell walls
 J must be reproduced in living cells
TAKS Question
What process is shown to the left?
 A Cellular ingestion
 B Pseudopod formation
 C Cell wall digestion
 D Binary fission
TAKS Question
Which of the following cannot metabolize
nutrients?
TAKS Question
What is the most common threat to a host
organism posed by an invading virus?
 A Production of viral fluids in the
bloodstream
 B Fermentation of acids in the digestive
system
 C Destruction of cells by viral reproduction
 D Stimulation of muscle tone in the heart
TAKS Question
Which of these does a virus need in order to
multiply?
 A Chloroplasts from a host cell
 B A host cell to provide oxygen for the virus
 C New ADP from a host cell
 D A host cell to replicate the virus’s DNA