Energy Conservation in Metabolism: The Mechanisms of ATP Synthesis

In living organisms, different types of energy are always interconverting into one another within the cell to allow the distinct cellular functions to be performed. This can be illustrated by several examples, such as the conversion of the energy of light into chemical energy in photosynthetic organisms or the chemical energy into mechanical energy in muscle contraction. Also, virtually all the cells need to use chemical energy to transport ions and other compounds across a membrane, generating a concentration gradient and thus converting chemical into osmotic energy. Finally, chemical energy is continuously converted in other forms of chemical energy during the biosynthesis of new molecules in cellular metabolism.