Question

The bacteria Lactobacillus acidophilus are frequently used in the production of yogurt. These bacteria use lactic acid fermentation when oxygen is not available. What would happen to the bacteria under anaerobic conditions if the lactic acid fermentation pathway were blocked?

A. The bacteria could no longer regenerate the NAD+ needed for glycolysis, so it would stop producing ATP.

B. The bacteria could no longer make the NADH needed for chemiosmosis, so it would stop producing ATP.

C. The bacteria could switch to using alcohol fermentation, so it would continue producing ATP.

D. The bacteria could switch to using the Kreb's cycle, so it would continue producing ATP.

Answer 1

A. The bacteria could no longer regenerate the NAD+ needed for glycolysis, so it would stop producing ATP.

Answer 2

The right answer is A.

Lactic fermentation is a catabolic process, a fermentation, having as a starting point glycolysis, which produces an acid, lactic acid used to reoxidize NADH to NAD+, and by the way it produces energy in form of ATP.

In other words, lactic acid fermentation is a biological process by which sugars such as glucose, fructose, and sucrose are converted into cellular energy and metabolic byproduct, lactate. It is a lactic ferment that intervenes.