Question

What happens when ATP supplies energy for thin filaments in a muscle fiber to slide over the thick filaments?

A. The muscle contracts.

B. The muscle relaxes.

C. The muscle both contracts and relaxes.

D. The muscle neither contracts nor relaxes

Answer 1

Answer: The correct answer is A) The muscle contracts.

During muscle contraction, the thin filaments ( actin filaments) slide pass over the thick filaments ( myosin) and the sarcomere ( unit of muscle contraction ) becomes short. This is explained through sliding filament theory.

Supply of energy in the form of ATP is very important for the contraction of muscle.

The role of ATP is to prepare myosin for its binding with actin by moving it to a state that has higher- energy. The thin filaments slide over the thick filaments and the contraction of muscle takes place.

Answer 2

The muscle contracts when ATP supplies energy for thing filaments in a muscle fiber to slide over thick filaments. The correct answer is A.