Question

The fate of pyruvic acid during aerobic respiration is
A. Lactic acid fermentation
B. Alcoholic fermentation
C. Oxidative decarboxylation
D. Oxidative phosphorylation

Answer 1

Hint: Glycolysis is the process where the glucose molecule is converted to two molecules of pyruvate and two hydrogen ions and two water molecules, and the fate of pyruvate which is the product of glycolysis is again different in both aerobic and anaerobic respiration.

Complete answer:
In glycolysis in order to produce the pyruvate so many reactions take place.
And this process is conducted in the cytoplasm of the cells and the enzymes required for them are present in the cytoplasm.
Along with pyruvate, so many by-products and energy molecules like ATP and NADH are formed in glycolysis.
The fate of pyruvate in aerobic respiration.
In aerobic respiration, the pyruvate which formed in the cytoplasm undergoes several reactions.
All these reactions were catalyzed by the pyruvate dehydrogenase enzyme.
The reaction which occurs is an irreversible reaction and occurs in the mitochondria.
Pyruvate is converted to hydro ethyl TPP, and this formed product again in the presence of enzyme dihydrolipoyl transacetylase it converts to the acetyl lipoamide, and in the presence of the enzyme dihydrolipoyl dehydrogenase which is converted to oxide lipoamide.
During these reactions, a nitrogen group catalyzes the acetyl group to Coenzyme A and finally forms the product Acetylco-A.
In this process of conversion of the pyruvate to acetyl CoA, 2 NADH molecules are produced.
And the process is called oxidative decarboxylation.
Mainly the reaction is controlled by the enzyme pyruvate dehydrogenase, it contains 5 Cofactors, they are NAD, FAD, TPP, lipoic acid and coenzyme A.

So, Correct option is C. Oxidative decarboxylation.

Note: In the aerobic respiration, the acetyl CoA which was produced enters the Krebs cycle and in the anaerobic respiration, pyruvate which is aldose form convert to keto form and it is finally converted to lactate in the presence of enzyme lactate dehydrogenase.