Which of these substances is required for contraction of smooth muscle fibres

Question

Quizplus · Accepted Answer

Calmodulin is required for contraction of smooth muscle fibres, as it activates myosin light chain kinase which in turn leads to cross-bridge cycling and contraction. Sodium and potassium ions are important for the generation and propagation of action potentials in muscle cells, but not for the actual contraction process. Myosin is a muscle protein that directly interacts with actin to produce muscle contraction, but it does not require smooth muscle contraction.

Which of These Substances Is Required for Contraction of Smooth