Most of the ATP Supplies for a Skeletal Muscle Undergoing

Question

Most of the ATP supplies for a skeletal muscle undergoing one 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 majority of ATP production in skeletal muscles comes from oxidative phosphorylation, which uses oxygen to generate ATP from the breakdown of glucose and fatty acids. Glycolysis and substrate phosphorylation also contribute to ATP production, but to a much lesser extent than oxidative phosphorylation. Creatine phosphate is a rapidly available source of ATP, but it can only sustain ATP production for a short period of time and is quickly depleted during prolonged exercise. De novo synthesis of ATP is not a significant source of ATP during exercise as the process is too slow.