Outline the functions of these four structural proteins during contraction of a sarcomere.
Paralytic drugs that bring about muscle paralysis are used in surgery to prevent the patient from moving. A commonly used paralytic drug is succinylcholine, which prevents muscle contraction. Succinylcholine can stop muscles from contracting because it has a similar shape to acetylcholine. Suggest how succinylcholine is able to prevent muscles contracting.
Duchenne muscular dystrophy (DMD) is a genetic disease caused by a single gene. DMD affects striated muscle, and symptoms of the disease first appear at an early age. The fibrous protein, dystrophin, stabilises muscle fibres during contraction. A person with DMD produces non-functioning dystrophin or no dystrophin at all. The disease occurs in about four in 100 000 people and mainly affects boys. Suggest and explain why boys are more likely to have DMD than girls.