Ontario Grade 12 University Biology (SBI4U) Course Practice Exam

Free energy is a term used to refer specifically to the amount of energy in a system that can be utilized to perform work. In biochemical contexts, this concept is crucial because it helps to understand how energy is transformed and transferred during chemical reactions. The two most commonly referenced types of free energy are Gibbs free energy and Helmholtz free energy, with Gibbs free energy being particularly important in biological systems.

This energy is significant because it determines the spontaneity of reactions; when the change in free energy is negative, a reaction can occur spontaneously, which means it releases energy that can be harnessed for cellular processes. In contrast, activation energy is the initial energy required to start a chemical reaction and does not represent the overall energy available for work once the reaction has proceeded. Transitional energy and kinetic energy describe different forms of energy that do not specifically pertain to the ability to perform work in the context of chemical reactions.