MICROANATOMY

Detailed explanation-1: -Answer and Explanation: The only energy source that can be used to power muscle activity is ATP which stands for adenosine triphosphate. In order to generate ATP, a process known as cellular respiration occurs in the presence of oxygen.

Detailed explanation-2: -Adenosine triphosphate (ATP) is the source of energy for all muscle contractions. Energy is released when ATP is broken into ADP+Pi (adenosine diphosphate and phosphate group). Maintaining the availability of ATP for muscle contraction is the limiting factor, since ATP is not stored in large amounts in skeletal muscle.

Detailed explanation-3: -Adenosine triphosphate (ATP) is the sole fuel for muscle contraction. During near maximal intense exercise the muscle store of ATP will be depleted in < 1s, therefore, to maintain normal contractile function ATP must be continually resynthesized.

Detailed explanation-4: -The main types of “fuel” used by muscle for energy metabolism are glycogen, glucose, and free fatty acids [1-3].

Detailed explanation-5: -The sources of ATP during muscle contraction in A-Level Biology include cellular respiration, the breakdown of glycogen stored in the muscle fibers, and the phosphocreatine system.