In which category would endergonic reactions typically fall?

Endergonic reactions are characterized by their requirement for energy input to proceed. These reactions result in products that have a higher free energy than the reactants, meaning they essentially absorb energy from their surroundings to drive the reaction forward. This energy absorption is often in the form of heat or other energy sources, making endergonic reactions fundamental in biological processes, such as photosynthesis, where energy from sunlight is harnessed to convert carbon dioxide and water into glucose and oxygen.

In contrast, other categories like energy releasing processes involve exergonic reactions, which are those that release energy—typically seen in cellular respiration. Energy neutral processes do not involve a net change in energy, while mildly exothermic processes, although they release some energy, do not fit the definition of requiring energy input like endergonic processes do.