Dictionary > Chemiosmotic hypothesis

Chemiosmotic hypothesis

Definition
noun
A theory postulated by the biochemist Peter Mitchell in 1961 to describe ATP synthesis by way of a proton electrochemical coupling.
Accordingly, hydrogen ions (protons) are pumped from the mitochondrial matrix to the intermembrane space via the hydrogen carrier proteins while the electrons are transferred along the electron transport chain in the mitochondrial inner membrane. As the hydrogen ions accumulate in the intermembrane space, an energy-rich proton gradient is established. As the proton gradient becomes sufficiently intense the hydrogen ions tend to diffuse back to the matrix (where hydrogen ions are less) via the ATP synthase (a transport protein). As the hydrogen ions diffuse (through the ATP synthase) energy is released which is then used to drive the conversion of ADP to ATP (by phosphorylation).
Supplement
This theory was not previously well accepted until a great deal of evidence for proton pumping by the complexes of the electron transfer chain emerged. This began to favor the chemiosmotic hypothesis, and in 1978, Peter Mitchell was awarded the Nobel Prize in Chemistry.
Also called: chemiosmotic theory
See also: chemiosmosis


You will also like...

Genetics and Evolution
Genetics and Evolution

Humans are diploid creatures. This means that for every chromosome in the body, there is another one to match it. Howeve..

Homo Species
The Homo Species

The evolution of the species of the genus "Homo" led to the emergence of modern humans. Find out more about human evolut..

Oligodendrocyte and Schwann cell
The Central Nervous System

Myelin sheath is essential for a faster conductivity of signals. Know more about this feature of some neurons in the Cen..

Types and Causes of Brain Damage
Types and Causes of Brain Damage

This tutorial describes the different types and causes of brain damage. Find out how genetics, physical injury, lack of ..

Birth Control and Contraception
Birth Control and Contraception

Different pregnancy and birth control and contraception strategies are described. Read this tutorial to learn each of th..

Ecosystem Succession
Ecosystem Succession

If the balance of nature is left untouched, landscapes can change dramatically over time. A previous ecosystem is supers..

Related Articles...

No related articles found

See all Related Topics