Question

2. In the citric acid cycle, malate is oxidized to oxaloacetate by the enzyme malate dehydrogenase, which uses NAD+ as an electron acceptor. In cells, the ratio of [NAD+]/[NADH] is kept very high. Given the following standard reduction potentials, explain why it is so important for cells to maintain this ratio. Justify your answer with words, equations and diagrams.

Answer 1

NAD+ act both as coenzyme as well as electron acceptor compound and get reduced to NADH by accepting electron.

Step-by-step explanation:

NAD+ act as co enzyme of various biological catalyst such as malate dehydrogenase, isocitrate dehydrogenase etc.

NAD+ can act as co enzyme only in its oxidized form but not in its reduced form called NADH.

Many reaction needs NAD+ to occur such as conversion of glyceraldehyde 3 phosphate to 1,3 bisphosphoglycerate, malate to oxaloacetate.

That"s why NAD+/NADH ratio is kept very high because if this ratio bychance get low then it will hamper the normal redox potential of NAD+/NADH.As a result many biochemical reaction will not take place.