The binding site on actin is exposed, and the transverse bridge is combined with actin, and the transverse bridge is twisted, dragging the filament to the center of the thick myofilament.
After the transverse bridge circulation process of combining, twisting, dissociating, recombining and twisting the transverse bridge with actin, the filaments continue to slide and the sarcomere is shortened. The energy of muscle contraction comes from the energy released by ATP hydrolysis.
Extended data:
There are three kinds of muscles:
The muscles of the heart are called myocardium. Due to the contraction and relaxation of the heart, the heart has been beating. The muscles of blood vessels, gastrointestinal tract, bladder, uterus, bronchus, pupils and hair roots are called smooth muscles. Smooth muscle has great ductility. It can stretch, expand and contract slowly and permanently.
The flesh and blood are connected, and the flesh and blood are often called the same. Because muscles are attached to bones, they are called skeletal muscles. Muscle fibers of skeletal muscle have many bright and dim stripes, so they used to be called striated muscles. However, some facial muscles are not attached to bones, but to skin. These muscles can be used to express various emotions, so they are also called expression muscles.
Through research, scientists believe that in the long process of evolution, smooth muscle appeared earlier, while skeletal muscle appeared at the latest. Skeletal muscles are fixed on bones through tendons, which drive bones and joints and make us make various postures and movements. When we put a piece of candy in our mouth, we must let the biceps brachii on our arm cooperate with other muscles to finish it.