A mutation in yeast makes it unable to convert pyruvate to ethanol. How will this mutation affect these yeast cells?
A) The mutant yeast will produce lactate under anaerobic conditions.
B) The mutant yeast will be unable to grow anaerobically.
C) The mutant yeast will be unable to grow aerobically.
D) The mutant yeast will grow anaerobically only when provided glucose.
E) The mutant yeast will be unable to metabolize glucose.

Question

Quizplus · Accepted Answer

When yeast cells are unable to convert pyruvate to ethanol, they will be unable to perform fermentation, which is their primary energy-producing pathway in the absence of oxygen. As such, the yeast cells will not be able to produce ATP via anaerobic respiration, which will result in their inability to grow anaerobically. However, the yeast cells will still be able to perform aerobic respiration if oxygen is present, since pyruvate can be converted into acetyl-CoA and enter the Krebs cycle. Therefore, choices A, C, D, and E can be eliminated.

A Mutation in Yeast Makes It Unable to Convert Pyruvate