Final answer:
An endergonic reaction requires an input of energy and is non-spontaneous.
Step-by-step explanation:
If a chemical reaction requires an input of energy rather than releasing energy, then the ΔG for that reaction will be a positive value. In this case, the products have more free energy than the reactants. Thus, the products of these reactions can be thought of as energy-storing molecules. These chemical reactions are called endergonic reactions, and they are non-spontaneous. An endergonic reaction will not take place on its own without the addition of free energy.
Let's consider the example of the synthesis and breakdown of the food molecule, glucose. In metabolism, the building of complex molecules, such as sugars, from simpler ones is called an anabolic process and requires energy. Therefore, the chemical reactions involved in anabolic processes are endergonic reactions. On the other hand, the catabolic process of breaking sugar down into simpler molecules releases energy in a series of exergonic reactions.