Final answer:
Cells use the hydrolysis of ATP to release energy that powers endergonic reactions, while enzymes lower the activation energy needed for these reactions to proceed quickly and efficiently.
Step-by-step explanation:
Cells overcome the energy requirement of endergonic reactions by hydrolyzing ATP. ATP, or adenosine triphosphate, is the primary energy currency of cells. When a cell needs to perform work, such as during endergonic reactions where the products have more free energy than the reactants, it can hydrolyze ATP, transforming it into ADP (adenosine diphosphate) and an inorganic phosphate. This hydrolysis releases energy that the cell can then use to power the endergonic reactions. Meanwhile, enzymes play a crucial role by lowering the activation energy of cellular reactions, both exergonic and endergonic, thereby increasing the reaction rates. Without enzymes, many necessary biochemical reactions would occur too slowly to sustain life. Activation energy is the threshold energy necessary to initiate a chemical reaction, and by reducing this energy requirement, enzymes make it possible for biochemical reactions to proceed quickly and efficiently at the temperatures found within living cells.