This powerpoint presentation covers viruses, bacteria, and other microbes. It begins by defining viruses as non-cellular particles composed of genetic material and protein that can infect living cells. Examples discussed include bacteriophages like T4 and viruses like herpes. Bacteria like E. coli are introduced as single-celled organisms distinct from viruses. The structures of viruses and bacteria are described, along with how bacteria reproduce through binary fission, conjugation, and forming spores. Different types of bacteria are classified by their energy production, respiration, and symbiotic relationships. The powerpoint concludes by discussing nitrogen fixation by bacteria.
5. Escherichia Coli Bacterium
E. coli is a bacterium. That is a crude cell, it is not a virus
because viruses are protein containers with DNA cores or
RNA cores.
6. E. Coli and the
Bacteriophage
What it looks like in real life
7. 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
11. A typical, "minimal" retrovirus
consists of:
•an outer envelope which
was derived from the plasma
membrane of its host
•many copies of an envelope
protein embedded in the lipid
bilayer of its envelope
•a capsid; a protein shell
containing
•two molecules of RNA and
•molecules of the enzyme
reverse transcriptase
13. Prokaryotes
Cells that do not have a
nucleus
Exist almost every where on
earth
Grow in numbers so great you
can see them with the unaided
eye
Are placed in either the
Eubacteria or the
Archebacteria Kingdoms
Make up the smaller of the two
kingdoms
15. Eubacteria
Make up the larger of
the two prokaryote
kingdoms
Generally are
surrounded by a cell
wall composed of
complex
carbohydrates
17. Archaebacteria
Lack important
carbohydrate found
in cell walls
Have different lipids
in their cell
membrane
Different types of
ribosomes
Very different gene
sequences
Archaebacteria can
live in extremely
harsh environments
They do not require
oxygen and can live
in extremely salty
environments as well
as extremely hot
environments.
21. Cellular Walls
Chemical nature of a cell wall can be determined
by Gram Staining
By finding out what color the cell produces when
it is gram stained you can figure out the type of
carbohydrates in the cell wall
22. Movement
• Flagella ~ Tail like structure
the whips around to propel the
bacterium
• Cillia ~ Miniature flagella
surround the cell that help to
“swim”
• Non motile ~ Sticky cillia like
structures that keep the
bacterium from moving
32. Conjugation
A type of Bacteria
Sex
Two organism swap
genetic information,
that contains the
information such as a
resistance to penicillin
33. Spore Formation: Endospore
A type of dormant cell
Exhibit no signs of life
Highly resistant to
environmental stresses such
as:
-High temperatures
-Irradiation
-Strong acids
-Disinfectants
Endospores are formed by
vegetative cells in response to
environmental signals that
indicate a limiting factor for
vegetative growth, such as
exhaustion of an essential
nutrient.
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