Problem 23

Background and context

Actin and myosin are the protein present in the muscle fibers that are responsible for the movement. The light (I-band) and dark (A-band) striations present in the myofilaments are due to the presence of actin and myosin. There is a line in the middle of the light bands known as the Z-line that marks the boundary of the sarcomere unit. The central part of the A-band is a little lighter than rest of the band and have a vertical line in the center known as the M-line.