An exergonic reaction is a reaction where there is a net negative change in free energy. This type of reaction is considered to be spontaneous, meaning that no energy has to be put into the system for a reaction to occur. This type of a reaction is favored because it releases energy that can be used by the cell. You can relate this concept to catabolism. Catabolic reactions start with reactants that have a high free energy and end with products that have a low free energy. Catabolism is the type of process in which ATP is generated. An endergonic reaction is a reaction in which there is a net positive change in free energy. This type of a reaction is not spontaneous and requires the input of energy to proceed. You can relate this concept to anabolism. Anabolism starts with reactants that have a low free energy and end with products that have a high free energy. This process take ATP to complete and for that reason is not favorable for the cell to carry out. A trick that I use to remember whether the reaction uses ATP is that anabolism and ATP both start with the letter A.
Recent comments