Final answer:
A reaction with a positive delta G requires energy input and is known as an endergonic reaction, which is non-spontaneous. Exergonic reactions release energy, have a negative delta G, and are spontaneous.
Step-by-step explanation:
A reaction that is (+deltaG) requires energy and is endergonic. In an endergonic reaction, the products possess a greater amount of free energy compared to the reactants. This greater free energy indicates that these reactions are non-spontaneous and do not occur on their own without an input of energy. For example, in metabolic processes, the synthesis of complex molecules like glucose from simpler ones requires energy and is an endergonic process, which is part of the broader anabolic function within cells.
Exergonic reactions, in contrast, have a negative delta G, releasing energy and are spontaneous. The term 'spontaneous' does not necessarily mean that an exergonic reaction happens instantly but that it is thermodynamically favorable and will proceed without an external input of energy over time. An everyday example of a spontaneous, exergonic reaction is the rusting of iron—it occurs slowly but inexorably.