Question

when is nad+ reduced to form nadh in glycolysis?
multiple choice
after cleavage of sugar
right before conversion to pyruvic acid
right before the cleavage step
first step of the process

Explanation:

In glycolysis, the reduction of \(NAD^{+}\) to \(NADH\) occurs during the conversion of glyceraldehyde - 3 - phosphate to 1,3 - bisphosphoglycerate. This step is right before the conversion to pyruvic acid. After sugar cleavage (formation of glyceraldehyde - 3 - phosphate from fructose - 1,6 - bisphosphate), the next major redox reaction (involving \(NAD^{+}\) reduction) happens before the final steps that lead to pyruvate formation. The first step of glycolysis is phosphorylation of glucose, and there is no \(NAD^{+}\) reduction then. And before the cleavage step (which is the formation of two three - carbon molecules from a six - carbon molecule), there is no \(NAD^{+}\) reduction.

Answer:

Right before conversion to pyruvic acid