Answer:
1. endergonic
2. exergonic
Step-by-step explanation:
The formation of ATP is an endergonic reaction. It means that the reaction requires the input of energy to be performed. Muscle cells form ATP mainly during the oxidative phosphorylation of cellular respiration. The proton concentration gradient across the inner mitochondrial membrane drives the endergonic phosphorylation of ADP into ATP. ATP hydrolysis releases energy and is an exergonic reaction. Removal of the phosphate group reduces the electrostatic repulsion between the negative charges present on the three phosphate groups of ATP.