MUSCLE PHYSIOLOGY

Detailed explanation-1: -The thick filament consists largely of myosin. Six proteins make up myosin: two heavy chains whose tails intertwine to form a supercoil and whose heads contain actin binding sites and a catalytic site for ATP hydrolysis. Two myosin light chains bind to each head region.

Detailed explanation-2: -The thick filaments of muscle consist of several hundred myosin molecules, associated in a parallel staggered array by interactions between their tails (Figure 11.23). The globular heads of myosin bind actin, forming cross-bridges between the thick and thin filaments.

Detailed explanation-3: -The thick filaments are composed of myosin with the globular heads forming cross-bridges with thin filaments.

Detailed explanation-4: -Thick filaments are composed of the protein myosin. The tail of a myosin molecule connects with other myosin molecules to form the central region of a thick filament near the M line, whereas the heads align on either side of the thick filament where the thin filaments overlap.

Detailed explanation-5: -The thick filament, myosin, has a double-headed structure, with the heads positioned at opposite ends of the molecule. During muscle contraction, the heads of the myosin filaments attach to oppositely oriented thin filaments, actin, and pull them past one another.