Question

A temporary oxygen deficit during strenuous exercise causes a muscle to

A) synthesize muscle proteins in response to steroid hormone stimulation.
B) synthesize glycogen.
C) ferment pyruvate to lactate.
D) switch to aerobic glycolysis.
E) synthesize more NAD+.

Answer 1

During strenuous exercise with a limited oxygen supply, muscles ferment pyruvate to lactate in a process known as lactic acid fermentation, allowing the muscle to continue producing ATP.

Step-by-step explanation:

During strenuous exercise, muscles may experience a temporary oxygen deficit due to the high energy demands. When there's not enough oxygen available for aerobic respiration, muscles switch to an anaerobic process. Lactic acid fermentation occurs where pyruvate is fermented to lactate. This temporary metabolic pathway is crucial as it allows the recycling of NADH into NAD+, which is necessary for glycolysis to continue producing ATP. This adaptation allows for continued muscle contraction despite the oxygen deficit. However, it can lead to muscle fatigue as lactic acid accumulates. Endurance training can increase the efficiency of this anaerobic process and improve overall muscle performance.