The Role of Ca²⁺ in the Control of Muscle Contraction

question 1

Multiple Choice

The role of Ca²⁺ in the control of muscle contraction is to

• A) cause depolarization of the T tubule system.
• B) initiate changes in protein conformation that expose myosin-binding sites on actin.
• C) change the conformation of myosin heads,thus causing microfilaments to slide past each other.
• D) bind to tropomyosin and break actin-myosin cross-bridges.
• E) block the ATP-binding site on myosin heads,enabling muscles to relax.