Microbiology multiple choice: 1. In addition to their ability to harvest light i
ID: 41728 • Letter: M
Question
Microbiology multiple choice:
1. In addition to their ability to harvest light in the 400 to 500 nm range, carotenoids also...
a. eject electrons from the reaction center.
b. function as a tetrapyrrole.
c. intercept toxic single-state oxygen.
d.transfer electrons to ubiquinone.
e. raise electrons to a higher energy state.
2. Photosynthetic halophiles use bacteriorhodopsin...
a. for oxygenic photosynthesis.
b. to trap light energy and eject protons.
c. as an accessory pigment.
d. to trap light energy in photosystems.
e. All of the above answers are correct.
3. In cyclic phosphorylation, ATP is formed when
a. sufficient protons are driven outside the membrane by the cytochrome bc1 complex.
b. ferredoxin nucleotide reductase is activated
c. protons are removed from outside the cell.
d. a second bacteriochlorophyll is excited.
e. bacteriochlorophyll a harvests light energy.
4. Which of the following can be used as a source of electrons in anoxic photosynthesis?
a. H2
b. H2S
c. H2O
d. Both a and b
e. Both b and c
5. Antenna pigments can be an advantage to photosynthetic microorganisms because they can
a. perform photosynthesis
b. absorb energy from light of different wavelengths, funneling energy of excitation to reaction centers.
c. perform photolysis of water and funnel energy to reaction centers.
d. absorb energy from light of different wavelengths and therefore increase the numbers of reaction centers.
e. transfer electrons to the electron transport chain.
6. All photosynthetic microorganisms possess all of the following features except
a. a capacity for substrate-level phosphorylation.
b. a light-gathering system.
c. an electron transport chain.
d. an ATP-generating system.
e. an electron donating system to generate NADPH.
7. The characterization of the bacteriorhodopsin system in Halobacterium lent support to
a. chromatic adaptation hypothesis.
b. the theory that animal rhodopsin evolved from bacteriorhodopsin.
c. the proton motive force hypothesis.
d. the endosymbiotic theory of evolution.
e. the chemiosmotic theory of ATP generation.
8. The thylakoid is a photosynthetic structure characteristic of
a. purple bacteria.
b. green sulfur bacteria.
c. green nonsulfur bacteria.
d. Heliobacterium.
e. cyanobacteria.
9. In noncyclic electron flow in nonsulfur purple bacteria, electrons leaving the Q pool
a. enter the TCA cycle.
b. are used to reduce NAD+.
c. are transferred to the cytochrome bc1 complex.
d. are used to generate a pmf.
e. are transferred to the cytochrome c2 protein.
10. During cyclic photosynthesis in nonsulfur purple bacteria, which of the following molecules or components acts as both the initial electron donor and the final electron acceptor?
a. Bacteriopheophytin
b. NADP+/NADPH
c. Cytochrome bc1 complex
d. Bchl 870
e. Ubiquinone
a. eject electrons from the reaction center.
b. function as a tetrapyrrole.
c. intercept toxic single-state oxygen.
d.transfer electrons to ubiquinone.
e. raise electrons to a higher energy state.
Explanation / Answer
1. c
2. b
3. a
4. d
5. b
6. a
7. e
8. e
9. b
10. d