Metabolism

Overview Metabolism represents all of the chemical activity in a cell, including reactions that build molecules (anabolism) and those that break …

The First Law of Thermodynamics states that energy cannot be created or destroyed, only transformed. This can be demonstrated within a classic food web …

The Second Law of Thermodynamics states that entropy, or the amount of disorder in a system, increases each time energy is transferred or transformed. …

Kinetic energy is the ability of an object in motion to do work or enact change. It can take on many forms. For instance, water flowing down a waterfall …

The energy stored by a structure and location of matter in space is called potential energy. For instance, raising a kettlebell changes its spatial …

Free energy—abbreviated as G for the scientist Gibbs who discovered it—is a measurement of useful energy that can be extracted from a reaction …

Activation energy is the minimum amount of energy necessary for a chemical reaction to move forward. The higher the activation energy, the slower the rate …

The bonds of adenosine triphosphate (ATP) can be broken through the addition of water, releasing one or two phosphate groups in an exergonic process …

The addition or removal of phosphate groups from proteins is the most common chemical modification that regulates cellular processes. These modifications …

Most chemical reactions in cells require enzymes—biological catalysts that speed up the reaction without being consumed or permanently changed. They …

Biochemical reactions are occurring constantly in cells, converting starting substances to different products, usually with the help of enzymes that speed …

Allosteric regulation of enzymes occurs when the binding of an effector molecule to a site that is different from the active site causes a change in the …

Enzymes require additional components for proper function. There are two such classes of molecules: cofactors and coenzymes. Cofactors are metallic ions …

Inhibitors are molecules that reduce enzyme activity by binding to the enzyme. In a normally functioning cell, enzymes are regulated by a variety of …

Enzymes speed up reactions by lowering the activation energy of the reactants. The speed at which the enzyme turns reactants into products is called the …