When skeletal muscle cells undergo anaerobic respiration, they become fatigued and painful. This is now known to be caused by
A) buildup of pyruvate.
B) buildup of lactate.
C) increase in sodium ions.
D) increase in potassium ions.
E) increase in ethanol.

Question

Quizplus · Accepted Answer

The buildup of lactate during anaerobic respiration causes fatigue and pain in skeletal muscle cells. Lactate accumulates when glucose is broken down without the presence of oxygen, leading to an increase in acidity in the cell and ultimately contributing to muscle exhaustion.

Answer: D 
 An increase in potassium ions is also a factor in muscle fatigue and pain during anaerobic respiration. As the muscle cell becomes more acidic due to the accumulation of lactate, potassium ions are released from the cell into the extracellular space. This can disrupt the cell's ability to transmit signals and eventually lead to muscle fatigue.

When Skeletal Muscle Cells Undergo Anaerobic Respiration, They Become Fatigued