FIU MCB3020 – GENERAL MICROBIOLOGY EXAM 1 VERSION

FIU MCB3020 – GENERAL MICROBIOLOGY EXAM 1 VERSION

Subject: Biology    / General Biology
Question
Answer questions 13, 17, 24, 29, 30, 31, 32, 36, 37

GENERAL MICROBIOLOGY EXAM 1 VERSION 1 FALL 2013
READ THE PROBLEM!
1. Substance A receives an electron from substance B. Substance A has been:
a. oxidized b. reduced
2. Substances A-E have the following Eo’ values: A = +0.4, B = – 0.3, C = 0, D = +0.6,
E = – 0.6. How would electron flow occur if these were part of an electron
transport chain?
a. A B C D E
d. E C B A D
b. D A C B E
e. B E A D C
c. E B C A D
3. In the above question, how much potential energy is available?
a. 1 volt b. 0.6 volt c. 1.9 volts d. 0 volts e. 1.2 volts
4. You are trying to prove that a bacterial isolate is the cause of a new emerging
disease, because every sick person you tested has the bacterium present and every
healthy person does not. Before calling the CDC you decide to test yourself, and
you find the bacterium even though you definitely are not sick with the disease.
You don’t make the call because you cannot fulfill which one of Koch’s Postulates?
a. first b. second c. third d. fourth e. fifth
5. If a microbe is growing on glucose and light it is a:
a. photoautotroph b. chemoautotroph c. photoheterotroph d. chemoheterotroph
6. If a microbe is growing by fermenting glucose it is a:
a. photoautotroph b. chemoautotroph c. photoheterotroph d. chemoheterotroph
7. How are electron carriers held in place in a membrane?
a. hydrophilic interactions c. both and an b
b. hydrophobic interactions d. none of the above
8. If you have an oxidation you also have to have:
+
a. pmf b. ATP c. a reduction d. NADPH + H e. a fermentation
9. You have a culture growing on 1 gram of yeast extract dissolved in 1 liter of
water. This medium is:
a. complex b. defined c. contaminated d. not a good one – nothing can grow in it
10. What types of microorganism can contain a monolayer in the cell membrane?
a. Bacteria b. Eukaryotes c. Archaea d. Viruses e. yeast
11. In the above question, what type of environment would this microbe be
expected to be growing in?
a. the ocean
c. an extreme environment such as very high temperature
b. an animal host d. an extreme environment such as very cold temperature
12. For the same question, what is the “monolayer” made of?
a. peptidoglycan c. glycerol tetraethers
e. fatty acids
b. pseudomurein d. glycerol diethers

13. What cannot diffuse across the wall of a gas vesicle?
a. water b. oxygen c. nitrogen gas d. CO e. CO2

14. Which of the following does not make a flagellated chemotactic microorganism
move up a gradient of an attractant?
a. a decrease in rate of autophosphorylation of CheA
b. an increase in rate of autophosphorylation of CheA
c. a biased change between CW and CCW direction of flagella rotation
d. an increase in runs vs. tumbles
e. higher binding of attractants to chemoreceptors
15. What directly makes the flagellar motor reverse direction?
a. the interaction of CheY~P with the flagellar motor
d. pmf
b. methylation of the MCPs
e. ATP
c. demethylation of the MCPs
16. CheA autophosphorylates before passing the phosphate to CheB. CheA is a(n)
____________ and CheB is a _____________.
a. attractant, repellant
c. sensor kinase, response regulator
b. response regulator, sensor kinase d. transducer, methyl group

17. If you look at a drawing of a bacterial membrane and on one side a lot of
protons are indicated, which side of the membrane is that one?
a. outside (periplasmic space or environment) b. inside (cytoplasm)

18. If the protons are in the periplasmic space, it is a species of:
a. Gram positive bacteria
d. Gram negative archaea
b. Gram negative bacteria
e. answers b or d are correct
c. Gram positive archaea
19. A membrane transport protein that moves substance A out while also moving
substance B in (at the same time) is an example of:
a. a uniporter b. a symporter c. an antiporter d. a co-transporter
20. In the above question, if B is a proton, what is powering the transport?
a. ATP b. pmf c. glucose d. the concentration of substance A
21. In the above two questions, this is an example of:
a. simple transport b. group translocation c. the ABC system
22. Which of the following is not present in bacterial cell walls?
a. n-acetylglusoamine
d. peptidoglycan
b. n-acetylymuramic acid
e. they are all present
c. n-acetylalosaminuronic acid
23. How is peptidoglycan held together?
a. hydrophobic interactions
d. covalent bonds
b. hydrophilic interactions
e. all of the above
c. a combination of hydrophobic and hydrophilic interactions

24. During both photosynthesis and respiration ATP is produced:
a. as a result of electron flow
d. by pmf
b. by substrate level phosphorylation
e. all except b
c. by protons moving through ATPase

25. Which will produce the most pmf?
a. an electron moving from a cytochrome to another cytochrome
b. an electron moving from a cytochrome to a quinone
c. an electron moving from an iron-sulfur protein to a cytochrome
d. an electron moving from a hydrogen carrier to another H carrier
e. a proton moving through Fo
26. In oxygenic photosynthesis, where is the electron donated?
+
a. PSI b. PSII c. NAD(P) H + H d. water e. oxygen
27. In oxygenic photosynthesis, what is the electron donor?
+
a. PSI b. PSII c. NAD(P) H + H d. water e. oxygen
28. Why is photosynthesis often modeled as a “Z scheme”?
a. because organization of the ETC in the membrane is like a Z
b. because one possible electron donor is Z
c. because when plotted on the electron tower the path of electron flow is like a Z
d. because it was discovered by Dr. Z
e. because the electron acceptor is Z

29. The third stage of fermentation is required to:
a. produce ATP
d. produce NAD+
+
b. produce NADH + H
e. produce pmf
+
c. produce ATP and NADH + H

30. How much ATP in total is produced by fermentation of one molecule of
glucose?
a. 1 b. 2 c. 3 d. 4 e. 6

31. How much actual ATP is produced by fermentation of one molecule of glucose?
a. 1 b. 2 c. 3 d. 4 e. 6

32. If the answers to the above two questions are different, why?
a. There are 6 carbons in glucose, but it is only partially oxidized
b. Some ATP is used in stage three to balance the oxidation/reduction
c. Some ATP is used in stage one to activate glucose
+
d. Some ATP is used in stage two to oxidize NADH + H

33. You are growing cells in a chemostat whose volume is 500 mls. You are
dripping media from the reservoir through the growth vessel at a rate of 1500 mls
per hour. How fast are the cells growing (doubling time)?
a. 20 minutes b. 1 hour c. 2 hours d. 3 hours e. 5 hours
34. You crank the rate of flow up to 4500 mls per hour, but notice shortly after
that the medium is clear. When you plate to count cells (viable count) nothing
grows. What happened?
a. you contaminated your culture with a virus when you increased the rate
b. the cells can’t grow fast enough
c. you washed the cells out
d. the cells are in lag phase – you just have to wait
e. both b and c 35. In batch culture, what happens to cells when they are in “stationary” phase?
a. they are growing exponentially
d. they have all formed spores
b. they are dead
e. they quit moving
c. they are alive but not growing

36. In quorum sensing, bacteria respond to:
a. individual chemicals (attractants, repellants) in the environment
b. a high concentration of individual chemicals (attractants, repellants) in the
environment
c. signaling molecules produced by bacteria
d. a high concentration of signaling molecules produced by bacteria

37. Autoinducers:
a. diffuse from inside the cell to outside the cell
b. diffuse from outside the cell to inside the cell
c. both of the above
d. are synthesized inside the cell and stay inside the cell
e. are actively transported outside of the cell and stay outside the cell

38. Most cells have a solute concentration of about 10 mM, much higher than that
of the environment. Why is this a potential problem?
a. It is hard to transport needed substances in because of the concentration
gradient.
b. Most environments have water present, which will diffuse across the membrane
because of the high solute concentration and cause cells to swell and burst
c. The proton motive force doesn’t work as well with such a high concentration of
solutes inside the cell
d. Cells can’t keep up metabolizing all of the solutes
e. Cells keep responding to these QS signals
39. In the above question, how do most cells resolve the problem?
a. by continually pumping the solute back outside the cell
b. by having semi-permeable membranes
c. by having rigid cell walls
d. by having porins that allow the solutes to move out
e. none of the above
40. What is the function of teichoic acids?
a. it keeps protons near the cell wall in Gram negative bacteria
b. it keeps protons near the cell wall in Gram positive bacteria
c. it keeps protons in the periplasmic space in Gram negative bacteria
b. it keeps protons in the periplasmic space in Gram positive bacteria