Sources of Atp

Muscle contractions are fueled by ATP (adenosine triphosphate) Figure 1. ATP is an energy storing molecule, available in several pools or forms to the muscle filaments. The immediate source of ATP can power only a few twitches. However, this pool is easily and quickly replenished for full muscle contraction and sustained exercise. Three sources supply the muscle's ATP pool: (1) creatine phosphate, (2) glycogen, and (3) cellular respiration in the mitochondria of the fibers Adenosine Triphosphate (ATP) is the immediate source of energy for muscle contraction. ATP provides chemical energy required for the automatic work of skeletal muscle contraction. The immediate source of ATP can power only a few twitches. However, it is easily and rapidly replenished for full muscle contraction and continued exercise. ATP is stored in the muscles cells, which is replenished during relaxation. Creatine phosphate, which reserves high-energy phosphate groups, is used after the first six seconds of exercising; it helps to convert adenosine diphosphate (ADP) to ATP. Anaerobic respiration, which breaks down nutrients and provides energy to phosphorylate ATP, occurs after ten minutes of exercising, it does not need oxygen and aerobic respiration, the breakdown of carbohydrates, occurs when the heart begins to beat faster to deliver oxygen that is needed.

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Muscles contract in a repeated pattern of binding and releasing between the two thin and thick strands of the sarcomere. ATP is critical to prepare myosin for binding and to "recharge" the myosinMuscles contract in a repeated pattern of binding and releasing between the two thin and thick strands of the sarcomere. ATP is critical to prepare myosin for binding and to "recharge" the myosin