BACTERIA AND VIRUSES
IDENTIFYING BACTERIA:
prokaryote: ______________-celled
no membrane bound _________________
much _________________ than eukaryotes
* eubacteria
"True" or ____________________ bacteria
_________________ group of the two (eubacteria/archaebacteria)
They can live _________________________
* archaebacteria = " _________________________"
look similar, but are different from eubacteria because:
_____ ________ don't have peptidoglycan
they have weird _____________(no other species in any
other kingdom has them)
DNA is more like a ____________________ than a
_________________
*Five ways of identifying prokaryotes:
1) ____________________________
*bacillus: ___________ shaped
*coccus: ___________ shaped
*spirillum (spirochete): ___________ shaped
2) _______________________ which ______________ cell from harm, found
_________________ cell membrane. There are sometimes a second cell
__________ found outside
peptidoglycan: Main part of cell __________, like cellulose in plants
Gram Stain: Way we identify what kind of cell wall by using ___________
(purple 1st, red 2nd)
*gram positive: Have ___________ of peptidoglycan, so soak up
purple, no room for red, so appear ______________
under the microscope.
*gram negative: Have a second, outer ____________ which repels
purple stain, so absorbs read and appear ______ under
microscope.
3) __________________________
*flagella: Long, whip-like __________ used to __________ ( ________
are short)
*slime layer: bacteria secretes this to ______________ through
*no movement: ___________ bacteria don't move at all
4) How bacteria obtain _____________________
Autotrophs:
*photoautotroph: Uses sunlight to _________________ (like plants)
*chemoautotroph: Uses energy from reactions of _______________
molecules to ______________
Heterotrophs:
*heterotrophs: Engulfs or breaks down food like ____________
*photoheterotroph: Does both __________________ and gets
other _____________ from environment
5) _____________________ Requirements
*obligate aerobes: Must have ____________________
(like us). Do aerobic _____________________
*obligate anaerobes: Cannot have ________________
Do ________________________
*facultative anaerobes: Prefer no __________ (anaerobic)
and do ________________, but can do aerobic
____________________ if necessary.
(They can _____________ back and forth)
*Other bacteria vocabulary:
*binary fission: _________________ reproduction; when bacteria gets too
________, it divides in _________ (like ________________)
*conjugation: Exchange of ______ though a hollow ___________ that
forms between two bacteria
*endospore: When conditions are ______ (antibiotics around, hot, dry,
etc.) some bacteria can form an ________________, which is a
_____________ that forms around DNA to ____________ it.
Bacteria can stay "dormant" like this up to 4 years until conditions
improve and they can start growing again.
BACTERIA IN NATURE: "The Good, the Bad, and the Ugly"
*Why do plants and animals need nitrogen?: to make _________________ to
make proteins.
*nitrogen fixation: Process that some bacteria do to turn _____________
in the environment into a ________________ form. This is an
example of _____________________
Pathogens: bacteria that cause harm or __________________
__________ of bacteria actually cause disease
*Two ways bacteria cause disease
1) produce a _____________ (poison): food poisoning is most commonly
caused by ________________________ toxins. Ex. Strep.
causes throat irritation, fever and Salmonella causes food poisoning,
and problems with the ________________ tract
2) tissue damage: infected host _______________ are damaged
Examples of pathogens:
M. tuberculosis: _________________ aerobe, destroys
_________ tissue
Yersina pestis: ______________ facultative anaerobe, causes
_____________
C. botulinum: ________________ anaerobe, produces
______________ toxin which is a neurotoxin that causes all
muscle to ________ (called "flaccid paralysis) MOST deadly
biological toxin!! BOTOX (originally used to help people with
muscle spasms) is a 1/1000 dilution
C. tetani: _________________ anaerobe, produces
______________ toxin which is a neurotoxin that causes all
muscles to stay flexed (called "rigid paralysis" or "lock jaw")
* Koch's Postulates: 4 Things to Identify What Causes a Disease
1. ________________ is present in _______ cases.
2. Pathogen can be ______________ and grown in culture.
3. The pathogen from culture will cause the disease when
_____________ into healthy animal.
4. The pathogen is __________________ from that sick animal
and shown to be the same as the _____________
pathogen.
*Human use of bacteria
- For __________: ex. ______________ (fermentation causes holes),
sauerkraut, vinegar, ____________ ("active cultures"), sourdough
bread, sour cream
- For _____-remediation: bacteria can ________________ oil spills, mines
- To make _____________________ : like human __________________
*Controlling Bacteria
-antibiotics: Chemicals that ____________________ growth/reproduction
of bacteria
-sterilization: kills bacteria by 1) __________ (cooking) or 2) __________
like disinfectants (which we cannot eat) or ______________(which
we can eat)
-disinfectants: Chemicals that ____________ bacteria
-chemical treatments (preservatives): sugar and salt (both _____________
solutions), or vinegar ( an _________ )
-refrigeration: cold ___________ bacterial growth (does NOT kill,
remember: food still goes bad in the refrigerator!!)
-canning: high heat, ____________ cans seal quickly, keeps canned food
from ________________ for long periods
VIRUSES
Virus: obligate ________________ that must infect a __________ cell;
made of protein coat (___________) and a __________ of DNA or RNA
so small, can only be seen with an _________________ microscope
cannot __________________ (That's why they need a host!)
Host cell: What virus _________________, takes over, and forces to make more
viruses
Examples of diseases caused by viruses: _______________________________
* typical structure of a virus
capsid: _________________ coat around virus
bacteriophage: a virus that only infects __________________
Lytic infection/cycle (Hallmark is "bursting immediately")
1. Virus land on/attaches
to _______ cell
2. Virus ____________ its
DNA (or RNA) into
host
4. Host puts together
virus _______________
3. Host starts making virus
parts using virus' ______
5. Host cell __________ ,
releasing new viruses
(this is called "shedding")
Lysogenic cycle
5. When "safe" (immune system is
down due to another disease,
stress, chemo), ________
will exit host DNA and
continue with _______ cycle
* prophage: _________ DNA that _________________itself into _________
DNA during ______________ cycle
Vaccines: __________________ (non-pathogenic) __________/virus, or pieces
of them that act as an __________________ that gets the body to make
____________________. Now you have in your blood antibodies ready to
attack the real pathogen if you get an infection.
2. Viral DNA forms _______
1
.
4. Viral DNA (now a ________)
will get copied along with
host DNA during mitosis
3. Viral DNA ___________ itself
into host DNA 3. Put new virus particles together
4. Viruses _____________
Oncogenic viruses (oncoviruses): Viruses that, when they insert themselves during
the ___________________ cycle, do so in a gene used to control
___________ cycle. A gene for a ________________ does not work
anymore! That causes Cancer. ("Onco" means cancer)
Retroviruses: Retro means "__________________". These viruses have
______, so first, they have to get host to make DNA from it using the
enzyme ______________________ transcriptase. This does
"transcription in reverse"!
RNA ---> DNA
Reverse Transcriptase: _________________ used by retroviruses to make DNA
from RNA
Prions: _______________ that infect; they go to the brain and make ________
"Scrapies" and "Mad Cow Disease" are examples