Exam 1 potential answers

Exam-answeres
1. Three of the five factors are:
a). Longevity dominance: bacteria live on earth around 3.5 billion yrs ago. A single bacterium can survice up to million of yrs.
b). Environmental dominance: Bacteria created about 20% O2 atmosphere thru photosynthesis.
c). Infectious diseases: In top 2 leading causes of death for human.
Hoa Le

2. Four components of of Koch's Postulates are:
a). Must find microbe in every patient w/ disease
b). Must take sample of microbe from patient grow in pure culture
c). Inoculate healthy animal w/ microbe, see same symptoms
d). must then be able to culture same microbe from expt: infected animal
Hoa Le

3. Please describe the process of gram staining?
1). Drop the bacterial broth on the slide and let it air dry
2). Let the heat fix the slide and make sure it is dry
3). Pour on the crystal violet making sure it is coving all the bacteria and let it sit for one minute
4). Rinse and blot
5). Pour on the gram iodine making sure it is covering all the bacteria and let it sit for one minute
6). Rinse and blot
7). Take ethanol and drop about 7-15 drops until it runs off of the slide clear then stop
8). Rinse and blot
9). Pour on the safranin making sure it si cover all the bacter and let it sit for one minute
10). Rinse and blot
Molly O'Neill

4. Why is tuburculosis sometimes called the vampire myth?
Tuburculosis makes you very thin and pale. It also makes you cough up blood so thats why a lot of people called tuburculosis the vampire myth.
Molly O'Neill

5. What is the difference between an antiseptic and a antibiotic?
A antiseptic you can only put on the outside of your body because an antiseptic will kill cells good or bad. So if you used it in your body
that would be bad cause it would kill all the good cells that your body does need.
A antibiotic is safe to put into your body. It will only kill the cells with the infection and it won't be toxic to you.
Molly O'Neill

6. Why cells are so small
Surface area to volume ratio. Cells use diffusion primarily to accept nutrients and to remove waste. A small cell can diffuse waste out and receive nutrients faster and more efficiently.

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9. Different of G+ and G- are:
a. Gram positive bacteria - peptidoglycan cell wall with LTA, and phospholipid membrane.
b. Gram negative bacteria -peptidoglycan cell wall with no LTA, plasma membrane, periplasmic space, and outermembrane with LPS.
-Hoa Le

10. Selective Media is media that prevents some bacteria from growing. One example of this is Mannitol Salt Agar because only bacteria that can live with a high salt environment can survive on this.
Differential Media is media that allows you to see whether the bacteria can eat different things. An example of this is the DNAse Agar, because if bacteria can break down DNA, then the agar changes from blue-green to clear where the bacteria are.
-Mackenzie D.

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13. Cocci are sphere shaped.
Bacilli are rod/cylinder shaped (1 axis is longer than the other axis)
Spirilla are longish flexible curled/corkscrew shaped rods
Spirochetes are slender corkscrew shaped that have an internal flagellum which makes them spin
like corkscrews
-Mackenzie D.

14. Staphylococci are gram positive cocci that grow in clusters like grapes.
Streptococci are gram positive cocci that look like beads on a string.
-Mackenzie D.

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