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Crista
 
 
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Cristae (singular crista) are the internal compartments formed by the inner membrane
Inner mitochondrial membrane

The mitochondrial inner membrane forms internal compartments known as cristae, which allow greater space for the proteins such as cytochromes to function properly and efficiently....
 of a mitochondrion
Mitochondrion

In cell biology, a mitochondrion is a membrane-enclosed organelle found in most eukaryote cell . These organelles range from 0.5–10 micrometers in diameter....
. They are studded with proteins, including ATP synthase
ATP synthase

An ATP synthase is a general term for an enzyme that can synthesize adenosine triphosphate from adenosine diphosphate and inorganic phosphate by using some form of energy....
 and a variety of cytochrome
Cytochrome

Cytochromes are, in general, membrane-bound hemoproteins that contain heme groups and carry out electron transport.They are found either as subunitss or as subunits of bigger enzymatic complexes that catalyze redox reactions....
s. The maximum surface for chemical reactions to occur is within the mitochondria. This allows cellular respiration
Cellular respiration

Cellular respiration is the set of the metabolism reactions and processes that take place in organisms' cell s to convert Energy from nutrients into adenosine triphosphate , and then release waste products....
 (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
Enzyme

Enzymes are biomolecules that catalysis chemical reactions. Almost all enzymes are proteins. In enzymatic reactions, the molecules at the beginning of the process are called Substrate , and the enzyme converts them into different molecules, the products....
.






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Mitochondrie
Cristae (singular crista) are the internal compartments formed by the inner membrane
Inner mitochondrial membrane

The mitochondrial inner membrane forms internal compartments known as cristae, which allow greater space for the proteins such as cytochromes to function properly and efficiently....
 of a mitochondrion
Mitochondrion

In cell biology, a mitochondrion is a membrane-enclosed organelle found in most eukaryote cell . These organelles range from 0.5–10 micrometers in diameter....
. They are studded with proteins, including ATP synthase
ATP synthase

An ATP synthase is a general term for an enzyme that can synthesize adenosine triphosphate from adenosine diphosphate and inorganic phosphate by using some form of energy....
 and a variety of cytochrome
Cytochrome

Cytochromes are, in general, membrane-bound hemoproteins that contain heme groups and carry out electron transport.They are found either as subunitss or as subunits of bigger enzymatic complexes that catalyze redox reactions....
s. The maximum surface for chemical reactions to occur is within the mitochondria. This allows cellular respiration
Cellular respiration

Cellular respiration is the set of the metabolism reactions and processes that take place in organisms' cell s to convert Energy from nutrients into adenosine triphosphate , and then release waste products....
 (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
Enzyme

Enzymes are biomolecules that catalysis chemical reactions. Almost all enzymes are proteins. In enzymatic reactions, the molecules at the beginning of the process are called Substrate , and the enzyme converts them into different molecules, the products....
. FADH2
Flavin

Flavin is the common name for a group of organic compounds based on pteridine, formed by the Heterocycle isoalloxazine. The biochemical source is the vitamin riboflavin....
 is also split into H+ ions, electrons, and FAD. As those electron
Electron

The electron is a subatomic particle that carries a negative electric charge. It has elementary particle and is believed to be a point particle....
s travel further through the electron transport chain
Electron transport chain

An electron transport chain couples a chemical reaction between an electron donor and an electron acceptor to the transfer of proton across a Cell membrane, through a set of mediating biochemical reactions....
 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
Intermembrane space

The intermembrane space is the region between the inner membrane and the outer membrane of a mitochondrion or a chloroplast. The main function of the intermembrane space is oxidative phosphorylation....
), creating an electrochemical gradient
Electrochemical gradient

An electrochemical gradient is a spatial variation of both electrical potential and chemical concentration across a membrane. Both components are often due to ion gradients, particularly proton gradients, and the result can be a type of potential energy available for work in a cell....
. As a result, chemiosmosis
Chemiosmosis

Chemiosmosis is the diffusion of ions across a selectively-permeable membrane. More specifically, it relates to the generation of Adenosine triphosphate by the movement of hydrogen ions across a inner membrane during cellular respiration....
 occurs, producing ATP
Adenosine triphosphate

This article is about the chemical used by cells as an energy carrier. For other uses, see ATP .Adenosine-5'-triphosphate is a multifunctional nucleotide, and plays an important role in cell biology as a coenzyme that is the "molecule unit of currency" of intracellular energy transfer....
 from ADP
Adenosine diphosphate

Adenosine diphosphate, abbreviated ADP, is a nucleotide. It is an ester of pyrophosphoric acid with the nucleoside adenosine. ADP consists of the pyrophosphate Functional group, the pentose sugar ribose, and the nucleobase adenine....
 and a phosphate group when ATP synthase
ATP synthase

An ATP synthase is a general term for an enzyme that can synthesize adenosine triphosphate from adenosine diphosphate and inorganic phosphate by using some form of energy....
 harnesses the potential energy
Potential energy

Potential energy can be thought of as energy stored within a physical system. It is called potential energy because it has the potential to be converted into other forms of energy, such as kinetic energy, and to do Mechanical work in the process....
 from the concentration gradient formed by the amount of H+ ions. H+ ions passively pass into the mitochondrian matrix
Matrix (biology)

In biology, matrix is the material between animal or plant cell , the material in which more specialized structures are embedded, and a specific part of the mitochondrion that is the site of oxidation of organic molecules....
 by the ATP synthase, and later on help to reform H2O.

The electron transport chain
Electron transport chain

An electron transport chain couples a chemical reaction between an electron donor and an electron acceptor to the transfer of proton across a Cell membrane, through a set of mediating biochemical reactions....
 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
Oxygen

Oxygen no O2 produced; 2) O2 produced, but absorbed in oceans & seabed rock; 3) O2 starts to gas out of the oceans, but is absorbed by land surfaces and formation of ozone layer; 4-5) O2 sinks filled and the gas accumulates]]...
 (O2), which combine with some of the hydrogen ions from the mitochondrian matrix through ATP synthase
ATP synthase

An ATP synthase is a general term for an enzyme that can synthesize adenosine triphosphate from adenosine diphosphate and inorganic phosphate by using some form of energy....
 and the electrons that had traveled through the electron transport chain. As a result they form two molecules of water
Water

Water is a common chemical substance that is essential for the survival of all known forms of life. In typical usage, water refers only to its liquid form or States of matter, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam....
 (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
Glycolysis

Glycolysis is the metabolic pathway that converts glucose, C6H12O6, into pyruvate, C3H5O3-....
 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
Glycolysis

Glycolysis is the metabolic pathway that converts glucose, C6H12O6, into pyruvate, C3H5O3-....
, 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
Sphere

A sphere is a symmetrical geometrical object. In non-mathematical usage, the term is used to refer either to a round ball or to its two-dimensional surface....
 shape
Shape

The shape of an object located in some space is the part of that space occupied by the object, as determined by its external boundary ? abstracting from other properties such as colour, content, and material composition, as well as from the object's other spatial properties ....
, and with less reaction surface available, the reaction efficiency would be likewise reduced. Therefore, cristae are a necessity for the mitochondria to function efficiently.