Endergonic means "absorbing energy in the form of work." Endergonic reactions are not spontaneous. By thermodynamic standards, work, a form of energy

Energy

In physics, energy is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems...

, is defined as moving from the surroundings (the external region) to the system

System

System is a set of interacting or interdependent components forming an integrated whole....

 (the internal region). Thus, an endergonic process, as contrasted with an exergonic

Exergonic

Exergonic means "releasing energy in the form of work". By thermodynamic standards, work, a form of energy, is defined as moving from the system to the surroundings...

 process, is one wherein the system absorbs energy from the surroundings. As a result, during an endergonic process, energy is put into the system. If the transformation occurs at constant pressure and temperature, ∆G > 0. An endergonic reaction

Endergonic reaction

In chemical thermodynamics, an endergonic reaction is a chemical reaction in which the standard change in free energy is positive, and energy is absorbed...

 is a chemical reaction

Chemical reaction

A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Chemical reactions can be either spontaneous, requiring no input of energy, or non-spontaneous, typically following the input of some type of energy, such as heat, light or electricity...

 that absorbs energy in the form of work. A good example of an endergonic reaction is photosynthesis

Photosynthesis

Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...

. Also, in metabolism

Metabolism

Metabolism is the set of chemical reactions that happen in the cells of living organisms to sustain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories...

, an endergonic reaction is anabolic, meaning, the storage of energy. In metabolism, catabolic and anabolic are coupled by ATP

Adenosine triphosphate

Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...

.

See also

• Exergonic
  Exergonic
  Exergonic means "releasing energy in the form of work". By thermodynamic standards, work, a form of energy, is defined as moving from the system to the surroundings...
  
  
• Exergonic reaction
  Exergonic reaction
  An exergonic reaction is a chemical reaction where the change in the Gibbs free energy is negative, indicating a spontaneous reaction. Symbolically, the release of Gibbs free energy, G, in an exergonic reaction is denoted as...
  
  
• Exothermic
  Exothermic
  In thermodynamics, the term exothermic describes a process or reaction that releases energy from the system, usually in the form of heat, but also in the form of light , electricity , or sound...
  
  
• Endothermic
  Endothermic
  In thermodynamics, the word endothermic describes a process or reaction in which the system absorbs energy from the surroundings in the form of heat. Its etymology stems from the prefix endo- and the Greek word thermasi,...
  
  

• Exothermic reaction
  Exothermic reaction
  An exothermic reaction is a chemical reaction that releases energy in the form of light or heat. It is the opposite of an endothermic reaction. Expressed in a chemical equation:-Overview:...
  
  
• Endothermic reaction
• Endotherm
  Warm-blooded
  The term warm-blooded is a colloquial term to describe animal species which have a relatively higher blood temperature, and maintain thermal homeostasis primarily through internal metabolic processes...
  
  
• Exotherm
  Warm-blooded
  The term warm-blooded is a colloquial term to describe animal species which have a relatively higher blood temperature, and maintain thermal homeostasis primarily through internal metabolic processes...