Concept:During intense exercise, oxygen supply becomes insufficient, so muscle cells produce energy by anaerobic respiration, forming lactic acid.
Explanation:In a 100 m race, the athlete’s muscles need a sudden, large amount of energy.
Oxygen cannot be supplied quickly enough for aerobic respiration.
So the muscle cells break down glucose without oxygen:
Glucose→Lactic acid+EnergyThis anaerobic respiration causes lactic acid to accumulate in the muscle cell fluid.
Therefore, the high lactic acid concentration is due to anaerobic respiration in the muscles during the race.
Answer:C. athlete’s muscle must have carried out anaerobic respiration during the race