The role of tropomyosin in skeletal muscle is ________.
A) blocking the active sites on the actin to regulate muscle contraction
B) the contracting unit
C) blocking the active sites on myosin to regulate muscle contraction
D) containing neurotransmitters

Question

Quizplus · Accepted Answer

Tropomyosin is a regulatory protein that blocks the active sites on the actin filament in a resting muscle, preventing the myosin head from binding to actin and initiating muscle contraction. When calcium levels in the muscle cell rise, calcium binds to the protein complex troponin, causing tropomyosin to shift position, exposing the active sites on actin and allowing muscle contraction to occur.

The Role of Tropomyosin in Skeletal Muscle Is ________