Crista

Jump to navigation Jump to search
Mitochondria structure :
1) Inner membrane
2) Outer membrane
3) Crista
4) Matrix

WikiDoc Resources for Crista

Articles

Most recent articles on Crista

Most cited articles on Crista

Review articles on Crista

Articles on Crista in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Crista

Images of Crista

Photos of Crista

Podcasts & MP3s on Crista

Videos on Crista

Evidence Based Medicine

Cochrane Collaboration on Crista

Bandolier on Crista

TRIP on Crista

Clinical Trials

Ongoing Trials on Crista at Clinical Trials.gov

Trial results on Crista

Clinical Trials on Crista at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Crista

NICE Guidance on Crista

NHS PRODIGY Guidance

FDA on Crista

CDC on Crista

Books

Books on Crista

News

Crista in the news

Be alerted to news on Crista

News trends on Crista

Commentary

Blogs on Crista

Definitions

Definitions of Crista

Patient Resources / Community

Patient resources on Crista

Discussion groups on Crista

Patient Handouts on Crista

Directions to Hospitals Treating Crista

Risk calculators and risk factors for Crista

Healthcare Provider Resources

Symptoms of Crista

Causes & Risk Factors for Crista

Diagnostic studies for Crista

Treatment of Crista

Continuing Medical Education (CME)

CME Programs on Crista

International

Crista en Espanol

Crista en Francais

Business

Crista in the Marketplace

Patents on Crista

Experimental / Informatics

List of terms related to Crista


Overview

Cristae (singular crista) are the internal compartments formed by the inner membrane of a mitochondrion. They are studded with proteins, including ATP synthase and a variety of cytochromes. The maximum surface for chemical reactions to occur is within the mitochondria. This allows cellular respiration (aerobic respiration since the mitochondria requires oxygen) to occur.

Electron transport chain of the cristae

NADH is split into NAD+, H+ ions, and electrons by an enzyme. FADH2 is also split into H+ ions, electrons, and FAD. As those electrons travel further through the electron transport chain in the inner membrane, energy is gradually released and used to pump the hydrogen ions from the splitting of NADH and FADH2 into the space between the inner membrane and the outer membrane (called the intermembrane space), creating an electrochemical gradient. As a result, chemiosmosis occurs, producing ATP from ADP and a phosphate group when ATP synthase harnesses the potential energy from the concentration gradient formed by the amount of H+ ions. H+ ions passively pass into the mitochondrian matrix by the ATP synthase, and later on help to reform H2O.

The electron transport chain requires a constant supply of electrons in order to properly function and generate ATP. However, the electrons that have entered the electron transport chain would eventually pile up like cars traveling down a one-way dead-end street. Those electrons are finally accepted by oxygen (O2), which combine with some of the hydrogen ions from the mitochondrian matrix through ATP synthase and the electrons that had traveled through the electron transport chain. As a result they form two molecules of water (H2O). By accepting the electrons, oxygen allows the electron transport chain to continue functioning.

The electrons from each NADH molecule can form a total of 2.5 ATPs from ADPs and phosphate groups through the electron transport chain, while each FADH2 molecule can produce a total of 1.5 ATPs. As a result, the 10 NADH molecules (from glycolysis and the Krebs cycle) and the 2 FADH2 molecules can form a total of 34 ATPs from this electron transport chain during aerobic respiration. This means that combined with the Krebs Cycle and glycolysis, the efficiency for the electron transport chain is about 65%, as compared to only 3.5% efficiency for glycolysis alone.

Usefulness

The cristae greatly increase the surface area on which the above mentioned reactions take place. If they were absent, the inner membrane would be reduced to a single spherical shape, and with less reaction surface available, the reaction efficiency would be likewise reduced. Therefore, cristae are a necessity for the mitochondria to function efficiently.

ca:Cresta mitocondrial de:Crista

Template:WH Template:WS