Microbiology Multiple Choice Questions on “Energy Production – Some Principles of Bioenergetics”.
1. The respiratory chain of bacteria is associated with the _____________
A. mitochondrial membrane
B. cytoplasmic membrane
C. cell wall
D. cytoplasm
Answer: B
Clarification: The respiratory chain of bacteria is associated with the cytoplasmic membrane and that of eukaryotes is present in the mitochondrial membrane.
2. The prosthetic group of a cytochrome contains how many iron atoms?
A. one
B. two
C. three
D. four
Answer: A
Clarification: Cytochromes are a major class of oxidative enzymes whose prosthetic group is a derivative of heme and contains a single iron atom, which is responsible for the oxidative or reductive properties of the enzyme.
3. Among the following which can directly react with oxygen?
A. cytochrome c
B. cytochrome c1
C. cytochrome a
D. cytochrome a3
Answer: D
Clarification: Cytochrome a and a3 together are called cytochrome oxidase, both of them contain copper. But only cytochrome a3 can react directly with oxygen.
4. How many ATP molecules are formed for per molecule of FADH2 reoxidized?
A. 3
B. 1
C. 2
D. 4
Answer: C
Clarification: Three ATP are formed per molecule of NADH2 reoxidized but only two ATP molecules are formed per molecule of FADH2 reoxidized, because of the high energy of NADH2.
5. In aerobic respiration the terminal electron acceptor is oxygen, nitrate, sulfate, etc.
A. True
B. False
Answer: B
Clarification: In aerobic respiration the terminal electron acceptor is oxygen; in anaerobic respiration the final electron acceptor is nitrate, sulphate and carbonate.
6. In photosynthesis by green plants, algae, cyanobacteria which of the following acts as terminal electron acceptor?
A. Water
B. Oxygen
C. NADP+
D. FAD+
Answer: C
Clarification: In photosynthesis by green plants, algae and cyanobacteria, water serves as a primary electron donor and NADP+ as a terminal electron acceptor.
7. A reducing agent will accept electrons and an oxidizing agent will donate electrons.
A. True
B. False
Answer: B
Clarification: An oxidizing agent will absorb electrons and will therefore become reduced whereas a reducing agent donates electrons, becoming oxidized in the process.
8. Keq is greater than 1.0 depending on which of the following conditions?
A. standard free energy change is negative
B. standard free energy change is positive
C. chemical reaction proceeds in reverse direction
D. products are not formed
Answer: A
Clarification: When standard free energy change is negative value then Keq is greater than 1.0 and the formation of products is favoured.
.