Chapter 32, Problem 32A

Summary Introduction

Introduction:

Adenosine Triphosphate (ATP) is the energy form that carries molecules present in the living cells. They carry chemical energy which they get from the breakdown of food molecules. This energy is released in the form of fuel for further cellular processes.

Answer to Problem 32A

Correct answer:

The correct answer is option (a) muscle contraction.

Explanation of Solution

Explanation/justification for the correct answer:

Option (a) muscle contraction requires ATP that is a form of energy. When the muscle contracts it breaks the myosin and actin bridge and releases myosin for further contraction. The muscle shortening goes when the myosin heads bind to actin and pull them towards themselves.

Explanation for incorrect answer:

Option (b) muscle relaxation doesn’t require ATP. As muscle relaxation relieves the tension as when a person breathes out. This process alters the tightness present in the muscles.

Option (c) muscle contraction requires ATP but its relaxation doesn’t require one. As in muscle relaxation work is not being done. So when a muscle relaxes it releases the strain that is already developed between the cells.

Option (d) neither muscle contraction nor relaxation is a wrong option as muscle contraction requires ATP but its relaxation doesn’t require one. The contraction of the muscle is a process where work is being done while the relaxation process isn’t doing any work.

Conclusion

Muscle contraction requires ATP as when they contract, they need the breakdown of energy while working.