Which of the following statements about the molecular arrangement of actin and myosin in myofibrils is false?
A) A thin filament consists of actin and tropomyosin.
B) Two chains of actin monomers are twisted into a helix.
C) Two strands of tropomyosin lie in the grooves of the actin.
D) Troponin forms the head of the myosin molecule.
E) The myosin heads have ATPase activity and interact with the actin.

Question

Quizplus · Accepted Answer

Troponin does not form the head of the myosin molecule. The head of the myosin molecule is formed by myosin itself, which interacts with actin filaments to generate muscle contraction. Troponin regulates the interaction between actin and myosin by binding to tropomyosin and allowing or preventing the interaction between the two proteins.

Which of the Following Statements About the Molecular Arrangement of Actin