What is energy releasing equation ?

I hope this helps you

Explanation:

ADP is combined with a phosphate to form ATP in the reaction ADP+Pi+free energy→ATP+H2O. The energy released from the hydrolysis of ATP into ADP is used to perform cellular work, usually by coupling the exergonic reaction of ATP hydrolysis with endergonic reactions.

answer; ///(b) it is composed of four protein chains and four heme groups;