Question

Which of the following happens in lactic acid fermentation?

Pyruvate is oxidized.

Pyruvate is reduced to lactic acid.

Nicotinamide adenine dinucleotide phosphate (NADPH) is regenerated.

Four adenosine triphosphate (ATP) molecules are produced.

Answer 1

In lactic acid fermentation, the following occurs:

**Pyruvate is reduced to lactic acid.**

This process involves the reduction of pyruvate, which is the end product of glycolysis, to lactic acid, and it also regenerates NAD+ from NADH, allowing glycolysis to continue. The other statements listed are not correct in the context of lactic acid fermentation:

- Pyruvate is not oxidized; it is actually reduced.
- NADPH is not directly involved in lactic acid fermentation; instead, NAD+ is regenerated.
- While ATP is produced during glycolysis (the initial step preceding fermentation), lactic acid fermentation itself does not produce four ATP molecules; it primarily serves to regenerate NAD+ to allow glycolysis to proceed and does not directly produce additional ATP after glycolysis.