Final answer:
The energy supplied in an endergonic reaction is stored in the products, which have higher free energy compared to the reactants. Endergonic reactions, being non-spontaneous, rely on energy inputs, typically sourced from the ATP within cells.
Step-by-step explanation:
When a chemical reaction requires energy to proceed, we are talking about an endergonic reaction. The energy supplied in an endergonic reaction becomes stored in the products, which have more free energy than the reactants. This means the products can be considered as energy-storing molecules. Endergonic reactions are non-spontaneous and will not occur without the addition of energy.
In cellular processes, these reactions are often driven by the energy released from the hydrolysis of adenosine triphosphate (ATP), which acts as a primary energy currency within the cell. ATP provides the necessary energy for endergonic processes, such as anabolism, active transport, and cell division. The energy from ATP is harnessed and used to convert reactants into products with higher free energy.