Question

Dystrophin is part of a multisubunit complex that links actin filaments in myofibrils to integral membrane proteins in the sarcolemma, which are also bound to the endomysium. This ensures that when the sarcomere shortens, the myofiber shortens, and that the force of shortening is transmitted to the muscle's connective tissue wrappings. What is the role of dystrophin in muscle contraction?

1) Dystrophin helps in the synthesis of actin filaments
2) Dystrophin links actin filaments in myofibrils to integral membrane proteins in the sarcolemma
3) Dystrophin is responsible for muscle relaxation
4)ystrophin is involved in the transmission of nerve impulses to the muscle fibers

Answer 1

Dystrophin's role in muscle contraction is to connect actin filaments to the sarcolemma, enabling the muscle fiber to contract efficiently when sarcomeres shorten.

Step-by-step explanation:

The role of dystrophin in muscle contraction is to link actin filaments in myofibrils to integral membrane proteins in the sarcolemma. These integral proteins are in turn connected to the endomysium, which is the connective tissue that surrounds each muscle fiber. This linking action by dystrophin ensures that when a sarcomere shortens during contraction, the entire muscle fiber shortens as well, allowing the force generated to be effectively transmitted to the muscle's connective tissue and thus produce movement.