True regarding excitation contraction coupling in smooth muscle is
Ans. (d) Presence of cellular calcium is essential to cause muscle contraction(Ref: Ganong, 25th ed/p.116)Troponin is absent in smooth muscleSustained contraction (latch) occurs with less use of ATPPhosphorylation of myosin is required for smooth muscle contraction
Presence of troponin is essential
Sustained contraction occurs with high calcium concentration
Phosphorylation of actin is required for contraction
Presence of cellular calcium is essential to cause muscle contraction
Muscle Physiology