Question

muscles need energy to contract. the immediate source of energy is provided by atp stored in the cells. the image shows the structure of atp. based on the image, enter the number of the bond that breaks first to release energy for the muscle cells to contract and relax.

Explanation:

Step1: Recall ATP energy - release mechanism

When ATP provides energy, the out - most phosphate bond is broken first. In the given structure, bond 4 is the out - most phosphate bond.

Answer:

4