The Immediate Source of Energy for Muscle Contractions Comes from _______

Question

The immediate source of energy for muscle contractions comes from _______.
A) lactic acid
B) oxygen
C) glucose
D) ATP

Accepted Answer

The immediate source of energy for muscle contractions comes from ATP (adenosine triphosphate), which is produced through cellular respiration using glucose and oxygen. Once the ATP is used up, the body must replenish it through other energy systems such as anaerobic glycolysis or oxidative phosphorylation. Lactic acid is produced during anaerobic respiration, but it is not the immediate source of energy for muscle contractions.