Most of the ATP Supplies for a Skeletal Muscle Undergoing

Question

Most of the ATP supplies for a skeletal muscle undergoing 1 hour of sustained exercise come from
A) creatine phosphate.
B) glycolysis.
C) substrate phosphorylation.
D) oxidative phosphorylation.
E) de novo synthesis.

Accepted Answer

During sustained exercise, the primary source of ATP for a skeletal muscle is oxidative phosphorylation, which occurs in the mitochondria and utilizes oxygen and glucose to produce ATP. The other options, such as creatine phosphate and glycolysis, provide ATP more rapidly but are limited in their ability to sustain ATP production for an extended period of time. Substrate phosphorylation and de novo synthesis are not significant sources of ATP during exercise.