MUSCLE PHYSIOLOGY

Detailed explanation-1: -So 1 molecule of pyruvate is responsible for the release of 2 CO2 molecules during 1 Krebs cycle. Since 1 glucose molecule gives 2 pyruvate molecules. There will be two cycles to utilize both the pyruvate molecules. Thus, 1 glucose molecule is responsible for the release of 4 CO2 molecules during Krebs cycle.

Detailed explanation-2: -The transition reaction connects glycolysis to the citric acid (Krebs) cycle. The transition reaction converts the two molecules of the 3-carbon pyruvate from glycolysis (and other pathways) into two molecules of the 2-carbon molecule acetyl Coenzyme A (acetyl-CoA) and 2 molecules of carbon dioxide.

Detailed explanation-3: -Because there’s two pyruvates formed after glycolysis, there will be two acetyl-CoA molecules formed, and therefore two rounds of the Krebs cycle. So the correct answer choice is (B), two turns.

Detailed explanation-4: -For one glucose molecules, there will be two rounds of Krebs cycle. This is because two molecules of Pyruvic acid are formed from one molecule of glucose during Glycolysis.

Detailed explanation-5: -In the presence of oxygen, a molecule of CO2 and two hydrogen atoms are split from pyruvic acid, and acetyl-coenzyme A (acetyl-CoA) is formed. Acetyl-CoA combines with oxaloacetic acid in the Krebs cycle to form the six-carbon atom citric acid.