Multiple Choice
In the photosynthetic archaean Halobacterium halobium, a membrane transport protein called bacteriorhodopsin captures energy from sunlight and uses it to pump protons out of the cell.The resulting proton gradient serves as an energy store that can later be tapped to generate ATP.Which statement best describes how bacteriorhodopsin operates?
A) The absorption of sunlight triggers a contraction of the β barrel that acts as the protein's central channel, squeezing a proton out of the cell.
B) The absorption of sunlight triggers a shift in the conformation of the protein's seven, membrane-spanning α helices, allowing a proton to leave the cell.
C) The absorption of sunlight triggers a restructuring of bacteriorhodopsin's otherwise unstructured core to form the channel through which a proton can exit the cell.
D) The absorption of sunlight triggers the activation of an enzyme that generates ATP.
Correct Answer:
Verified
Correct Answer:
Verified
Q38: Some lipases are able to cleave the
Q39: Indicate whether the following statements are TRUE
Q40: A bacterium is suddenly expelled from a
Q41: Indicate whether the following statements are TRUE
Q42: Cholesterol can either make membranes more rigid
Q44: Which of the following substances is most
Q45: Which of the following statements about the
Q46: Consider the apical location of a particular
Q47: Water molecules readily form hydrogen bonds with
Q48: For each of the following sentences,