This set of Microbiology Questions and Answers for Experienced people focuses on “Utilization of Energy in Nonbiosynthetic Processes”.
1. Which of the following has no detectable ATPase activity?
b) eukaryotic flagella
c) bacterial flagella
Explanation: Bacterial flagella appears to have no machinery for interconverting chemical and mechanical energy.Flagellin, the flagellar protein molecule, has no enzymatic activity i.e. no detectable ATPase activity.
2. Which force drives the flagellar rotation in bacteria?
b) protonmotive force
d) water gradient
Explanation: The flagellar motor is driven by the protonmotive force, i.e., the force derived from the electric potential and the hydrogen gradient across the cytoplasmic membrane and not ATP.
3. Rotary motor of flagella is associated with _________
a) M ring
b) P ring
c) L ring
d) M and S ring
Explanation: The rotary motor is believed to be the two elements in the basal body, the M ring and the S ring.The rod (which is connected to the filament by the hook) is fixed rigidly to the M ring, which rotates freely in the cytoplasmic membrane.The S ring is mounted rigidly on the cell wall.
4. Passive diffusion requires the use of membrane transport proteins for the transport of solute molecules across the membrane.
Explanation: In passive diffusion no substance in the membrane interacts specifically with the solute molecules. The difference in concentration gradient governs the rate of inward flow of solute molecules.
5. The entry of glycerol into the bacterial cells is by ____________
a) passive diffusion
b) facilitated diffusion
c) group translocation
d) active diffusion
Explanation: The entry of glycerol into the bacterial cells is an example of facilitated diffusion which involves the use of a specific protein carrier molecule called a porter for the diffusion of solutes.
6. Porter or permease is located in the _______________
a) cytoplasmic membrane
b) cell membrane
c) nuclear membrane
d) outer membrane
Explanation: Porter or permease is a specific protein carrier molecule which is required in facilitated diffusion which combines reversibly with the solute molecules and releases it into the inside of cell.
7. Facilitated diffusion does not require metabolic energy.
Explanation: Both the passive diffusion and facilitated diffusion does not require metabolic energy.
8. The reaction for the transfer of phosphoryl group of phosphoenol pyruvate to the sugar molecule requires which ion?
Explanation: The reaction for the transfer of phosphoryl group of phosphoenol pyruvate to the sugar molecule requires Mg2+, the products formed are sugar phosphate and pyruvate.
9. HPr stands for ______________
a) heat-stable carrier protein
b) hydrogen carrier protein
c) pyruvate dehydrogenase
d) high-energy protein
Explanation: Heat-stable protein (HPr) is activated first by transfer of phosphate group from the high-energy compound phosphoenol pyruvate inside the cell.
10. In phosphotransferase system(PTS), the sugar-phosphate is released inside the cell by which of the following?
a) Enzyme I
b) Enzyme II
c) Enzyme III
Explanation: Enzyme II is specific for a particular sugar, and is an integral component of the cytoplasmic membrane. Here it combines with the phosphate group carried by the activated HPr.The sugar-phosphate is released by enzyme II and enters the cell.
11. Mannitol enzyme II has been purified from _____________
b) Salmonella typhimurium
c) Saccharomyces cerevisiae
Explanation: Mannitol enzyme II has been purified from E.coli. Other enzymes can be purified from several other bacteria.
Sanfoundry Global Education & Learning Series – Microbiology.
To practice all areas of Microbiology for Experienced people, here is complete set of 1000+ Multiple Choice Questions and Answers.