Exercise · Q6
Q.Role of calcium in muscle contraction is ..........
(a) to break the cross bridges as a cofactor in the hydrolysis of ATP
(b) to bind with troponin, changing its shape so that the actin filament is exposed
(c) to transmit the action potential across the neuromuscular junction
(d) to re-establish the polarisation of the plasma membrane following an action potential
Maharashtra MsbshseTextbookSubjectiveImportance★★★★★est
25% · 6/24 Questions
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Start your 14-day free trial to unlock the full solution →Step 1. In a resting muscle, the troponin-tropomyosin complex physically covers the sites on the actin filament where myosin heads would otherwise bind, so no cross-bridge formation can occur.
Step 2. When calcium ions are released into the sarcoplasm following a nerve impulse, they bind to troponin (which has a strong affinity for calcium). This binding changes troponin's shape, which in turn shifts tropomyosin off the actin filament. …
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