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...

bryophyte - sporophyte and gametophyte
Meiosis and Alternation of Generations

Plants are characterized by having alternation of generations in their life cycles. This tutorial is a review of plant m..

Sigmund Freud and Carl Gustav Jung
Sigmund Freud and Carl Gustav Jung

In this tutorial, the works of Carl Gustav Jung and Sigmund Freud are described. Both of them actively pursued the way h..

Structural depiction of catalase, an enzyme
Protein Activity and Cellular Metabolism

Proteins have a crucial role in various biological activities. Get to know how proteins are able to perform as enzymes, ..

river
Running Water Freshwater Communities

This tutorial introduces flowing water communities, which bring new and dithering factors into the equation for possible..

Population Growth and Survivorship
Population Growth and Survivorship

This lesson looks at population attributes, regulation, and growth. It also covers population genetics, particularly gen..

Physical growth
Physical Development in Humans

This tutorial elaborates on the physical development of humans, particularly from puberty to adulthood. Read this tutori..

Related Articles...

No related articles found

See all Related Topics