Question

the mechanism of contraction in smooth muscle is different from skeletal muscle in that _______. a) atp energizes the sliding process b) the trigger for contraction is a rise in intracellular calcium c) the site of calcium binding site differs d) actin and myosin interact by the sliding filament mechanism

Explanation:

• In skeletal muscle, calcium binds to troponin.
• In smooth muscle, calcium binds to calmodulin.
• Both use ATP for the sliding process (A is wrong).
• Both have a rise in intracellular calcium as a trigger (B is wrong).
• Both use the sliding - filament mechanism (D is wrong).

Answer:

C. the site of calcium binding site differs