Dictionary > Chemiosmotic coupling hypothesis

Chemiosmotic coupling hypothesis

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).
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 hypothesis
See also: chemiosmosis, mitochondrion

You will also like...

Genetics – Lesson Outline & Worksheets
Genetics – Lesson Outline & Worksheets

  Topics Modules Quizzes/Worksheets Description Introduction to Genetics Genetics – Definition: Heredity and ..

A Balanced Vitamin Diet – Vitamins A – K

A balanced diet is essential to a healthy organism. Insufficiency or too much of a particular element or compound, such ..

Schematic diagram of DNA replication
DNA Structure & DNA Replication

DNA is a double helix structure comprised of nucleotides. A nucleotide, in turn, is made up of phosphate molecule, deoxy..

Darwin's Finches - Natural Selection
Darwin and Natural Selection

This tutorial investigates the genetic diversity in more detail. It also delineates how certain alleles are favored over..

Angle Oak Tree
Seed Plants

Seed plants are vascular plants. They differ from the other vascular plants in producing seeds that germinate into a new..

Early Mammals on Earth
Early Mammals on Earth

The Earth's ecosphere was rapidly changing and throwing up a wide range of ecological niches that new adaptive organisms..

Related Articles...

No related articles found

See all Related Topics