Question

question 5 (1 point) in order to stimulate a muscle fiber to contract, where should calcium bind to and what should happen as a result? g - actin; rolls away troponin to reveal active site on tropomyosin g - actin; rolls away tropomyosin to reveal active site on troponin tropomyosin; rolls away troponin to reveal active site on g - actin troponin; rolls away tropomyosin to reveal active site on g - actin

Explanation:

In muscle contraction, calcium binding to troponin initiates a series of events. Troponin is associated with tropomyosin which blocks the myosin - binding sites on G - actin. When calcium binds to troponin, it changes shape and moves tropomyosin, exposing the active sites on G - actin for myosin interaction.

Answer:

When calcium binds to troponin, troponin undergoes a conformational change. This causes tropomyosin to roll away from the active - site on G - actin, revealing the active site for myosin binding. So the correct answer is: G - actin; rolls away tropomyosin to reveal active site on G - actin.