Myosin: Each myosin (thick) filament is a polymerised protein with Meromyosin as monomeric proteins. Each meromyosin has two parts:
A. Heavy meromyosin (HMM): Globular head with a short arm. It projects outwards at regular intervals and angle from the surface of a polymerised myosin filament and is known as cross arm. The globular head is an active ATPase enzyme which has binding sites for ATP and active sites for actin.
B. Light meromyosin (LMM): Tail