Question

Prolonged activation of striated muscle causes it to fatigue. What is the reason?

• A. Breakdown of glycogen into lactic acid in muscle during aerobic respiration
• B. Breakdown of lactic acid in muscle during anaerobic respiration
• C. Breakdown of lactic acid into glycogen during anaerobic respiration
• D. Produce ethanol in muscle

Answer 1

Answer: (B)

Breakdown of lactic acid in muscle during anaerobic respiration

• Generally, the glucose undergoes metabolism in the presence of oxygen to form ATP (adenosine triphosphate) which is essential for the muscle contraction but during vigorous exercise, the body cannot meet the oxygen demand and the glucose undergoes metabolism in the absence of oxygen (anaerobic respiration)which results in the formation and accumulation of lactic acid. The breakdown of lactic acid in muscle causes the muscle to fatigue.
  
• Hence prolonged activation of striated muscle causes it to fatigue because of breakdown of lactic acid in muscle during anaerobic respiration.
  
• So, the correct answer is 'Breakdown of lactic acid in muscle during anaerobic respiration'.