Question

The main difference between lactic acid fermentation and alcoholic fermentation is that lactic acid fermentation a. produces more energy than alcoholic fermentation. b. produces less energy than alcoholic fermentation. c. regenerates NAD⁺ but alcoholic fermentation does not. d. regenerates a two-carbon molecule, but alcoholic fermentation does not. e. regenerates a three-carbon molecule and alcoholic fermentation does not.

Answer 1

Answer:

e. regenerates a three-carbon molecule and alcoholic fermentation does not.

Explanation:

Lactic acid fermentation includes the reduction of pyruvate into lactate. Lactate is a three-carbon molecule. Reduction of pyruvate into lactate also regenerate NAD+ required to continue the process of glycolysis.

Alcoholic fermentation includes decarboxylation of pyruvate into acetaldehyde followed by its reduction of alcohol. The alcohol formed as end product is a two-carbon molecule (ethanol). Here, NADH serves as electron donor and is oxidized into NAD+. Therefore, both the process regenerate NAD+ but ethanol fermentation does not regenerate the three-carbon molecule since one carbon is lost as CO2.