ATP supplies the energy for muscle contractions. part of the myosin head acts as ATPase and can hydrolyse ATP into ADP and inorganic phosphate which releases energy.
the myosin head attaches to the actin filament which forms a cross bridge
2. the myosin head tilts backwards, this causes the thin filament to slide past the myosinfilament. this is the power stroke. during the power stroke, ADP and inorganic phosphate are released from the myosin head.
3. after the power stroke, a new ATP molecule attaches to the myosin head- this breaks the cross bridge.
4. the myosin head then swings forward and back into it's original position as ATP is hydrolysed, this releases the energy to make this movement occur. the myosin head can now make a new cross bridge further along the actin filament.
