User:UTK443/New sandbox

ATP in muscle contraction:

ATP fuels muscle contractions. Muscle contractions are regulated by signaling pathways as a response to depolarization, activation of GPCRs and other stimuli. Different muscle types are regulated by specific pathways and stimuli based on their particular function. However, in all muscle types, contraction is performed by the proteins actin and myosin.

ATP is initially bound to myosin. When ATPase hydrolyzes the bound ATP into ADP and inorganic phosphate (Pi), myosin is positioned in a way that it can bind to actin. Myosin bound by ADP and Pi forms cross-bridges with actin and the subsequent release of ADP and Pi releases energy (the power stroke). The power stroke causes actin filament to slide past the myosin filament, shortening the muscle and causing a contraction. Another ATP molecule can then bind to myosin, releasing it from actin and allowing it to repeat this process again.

In such a way,