MUSCLE PHYSIOLOGY

Detailed explanation-1: -Mitochondria are the major site of oxidative metabolism, and hence ATP synthesis, in eukaryotic cells. Thus, whereas the glycolytic metabolism of glucose generates 2 ATP molecules, 36–38 are generated by the reactions of the citrate cycle and the oxidation of the resulting NADH and FADH2 by the respiratory chain [1].

Detailed explanation-2: -The classic role of mitochondria is oxidative phosphorylation, which generates ATP by utilizing the energy released during the oxidation of the food we eat. ATP is used in turn as the primary energy source for most biochemical and physiological processes, such as growth, movement and homeostasis.

Detailed explanation-3: -During strenuous exercise, the rate of energy use in skeletal muscles can increase by more than 100-fold almost instantly. To meet this energy demand, muscle cells contain mitochondria. These organelles, commonly referred to as the cell’s “power plants, ‘’ convert nutrients into the molecule ATP, which stores energy.

Detailed explanation-4: -The mitochondrial ATP synthase is a membrane protein complex that generates most of the ATP in eukaryotic cells. The synthesis of ATP from ADP and inorganic phosphate proceeds via rotary catalysis, which uses the energy of the electrochemical gradient across the mitochondrial inner membrane.

Detailed explanation-5: -The classic model of metabolic regulation during muscle contraction states that accelerating ATP utilization leads to increasing concentrations of ADP and Pi, which serve as substrates for oxidative phosphorylation and thus accelerate ATP synthesis.