During muscle contraction, ATP supplies energy for

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During muscle contraction, ATP supplies energy for the movement of myofilaments, which slide past each other and shorten the muscle fiber. ATP is hydrolyzed by the myosin ATPase in the myosin heads to provide the energy for the power stroke, which causes the myosin heads to bind to actin and move the thin filament. ATP also supplies energy for the calcium pump that returns calcium ions to the sarcoplasmic reticulum, for the sodium-potassium pump that maintains the resting membrane potential, and for other enzyme activities involved in muscle metabolism. Creatine phosphate, which can transfer a phosphate group to ADP to produce ATP, is a short-term energy store that supplements the ATP supply during the initial stages of muscle contraction. Glycogen is a polysaccharide that is stored in skeletal muscle and liver as a long-term energy source, but it needs to be broken down into glucose and then converted to ATP by glycolysis and oxidative phosphorylation.

During Muscle Contraction, ATP Supplies Energy for