When a muscle contracts anaerobically, more lactic acid is formed than when it contracts aerobically because:
When a muscle contracts anaerobically, more lactic acid is formed than when it contracts aerobically because:
a) oxygen inhibits fermentation of pyruvate to lactate.
b) under anaerobic conditions, most pyruvate is fermented to ethanol.
c) under aerobic conditions, most pyruvate is oxidized to CO
by the critic acid cycle.
d) glycolysis does not occur to a significant extent under aerobic conditions.
e) it’s been paralyzed by a 3000-fold excess of Botox.
Answer
The correct answer is:
c) under aerobic conditions, most pyruvate is oxidized to CO₂ by the citric acid cycle.
Explanation:
When muscles contract anaerobically (in the absence of oxygen), pyruvate, the end product of glycolysis, cannot enter the citric acid cycle and is instead converted into lactic acid. Under aerobic conditions, oxygen is available, and pyruvate is transported into the mitochondria, where it is fully oxidized to carbon dioxide (CO₂) in the citric acid cycle. This reduces the amount of pyruvate available to be converted into lactic acid, leading to less lactic acid formation.
Sourav
