Navigation Links
Oxidative phosphorylation

Oxidative phosphorylation is a biochemical process in cells. It is the final metabolic pathway of cellular respiration, after glycolysis and the citric acid cycle.

The process takes place at a biological membrane. In prokaryotes this is the plasma membrane, and in eukaryotes it is the inner of the two mitochondrial membranes. NADH and FADH2, electron carrier molecules that were "loaded" during the citric acid cycle, are used in an intricate mechanism (involving NADH-Q reductase, cytochrome c oxidase, and cytochrome reductase) to pump H+ across the membrane against a proton gradient.

A large protein complex called ATP synthase is embedded in that membrane and enables protons to pass through in both directions; it generates ATP when the proton moves with (down) the gradient, and it costs ATP to pump a proton against (up) the gradient. Because protons have already been pumped into the intermembrane space against the gradient, they now can flow back into the mitochondrial matrix via the ATP synthase, generating ATP in the process. The reaction is:

ADP3- + H+ + Pi ↔ ATP4- + H2O

Each NADH molecule contributes enough proton motive force to generate 3 ATP. Each FADH2 molecule is worth 2 ATP. All together, the 10 NADH and 2 FADH2 molecules contributed through oxidation of glucose (glycolysis, conversion of pyruvate to acetyl-CoA, and the Krebs cycle) account for 34 of the 38 total ATP energy carrier molecules. It is worth noting that these ATP values are maximums, in reality each NADH molecule contributes between 2 and 3 ATP, while each FADH2 contributes a maximum of 2 ATP.

Reactive oxygen species

Several highly reactive, transient oxygen derivatives can be formed during this process:

  1. Hydrogen peroxide
  2. Superoxide anion
  3. Hydroxyl radical


(Date:9/24/2015)... 24, 2015 Publiceringsförbud ... Kerv ( ), ... idag världens första kontaktlösa betalningsring på ... 000 GBP för massproduktion via crowdfunding.  ... , Kerv-bärare kan göra direkta ...
(Date:9/10/2015)... Conn. , Sept. 10, 2015  NXT-ID, Inc. ... biometric authentication company focused on the growing mobile commerce ... based ecommerce site, Touch of Modern, will feature ... Wednesday, September 16 th . ... wide range of designer lifestyle products to its 7.2 ...
(Date:9/2/2015)... 2015 Security of data and assets ... government organizations, telecommunications, hospitals, as well as individuals. ... being used to prevent unauthorised access. Technological advancements ... individuals could gain access to secure premises after ... hardware devices and numeric codes. However, hackers also ...
Breaking Biology News(10 mins):Första kontaktlösa betalningsringen lanseras på Kickstarter 2Första kontaktlösa betalningsringen lanseras på Kickstarter 3Första kontaktlösa betalningsringen lanseras på Kickstarter 4NXT-ID's Wocket Smart Wallet to be Offered by Touch Of Modern 2NXT-ID's Wocket Smart Wallet to be Offered by Touch Of Modern 3Global Biometrics Spending Market in the Government Sector 2015-2019 2Global Biometrics Spending Market in the Government Sector 2015-2019 3
... Since the human response to infection is highly ... facilitated by studying how similar processes occur in simpler ... disease, since they are easily handled, maintained and manipulated ... conserved. In addition, the small zebrafish embryo is highly ...
... National Institutes of Health (NIH) Transformative R01 Program ... Case Western Reserve University School of Medicine. The ... inborn genetic susceptibility to the development of colon ... only 42 recipients of this competitive new grant ...
... a dominant species in eastern U.S.,s forests before a blight ... returned to the landscape thanks in part to work by ... Improvement Program (UT TIP). Once used extensively for ... for humans and wildlife, and even as nutritious fodder for ...
Cached Biology News:Fish fend off invading germs with an initial response similar to the one found in people 2Prestigious $4.9 million NIH grant awarded to Case Western Reserve for colon cancer research 2Tennessee foresters helping to return chestnuts to American forests 2
Other biology definitionOther Tags