Mitochondrial matrix - wikipedia Mitochondrial matrix Cell biology The mitochondrion Components of a typical mitochondrion 1 Outer membrane 1.1 Porin 2 Intermembrane space 2.1 Intracristal space 2.2 Peripheral space 3 Lamella 3.1 Inner membrane 3.11 Inner boundary membrane 3.12 Cristal membrane 3.2 Matrix ◄ You are here 3.3 Cristæ 4 Mitochondrial DNA 5 Matrix granule 6 Ribosome 7 ATP synthase In the mitochondrion, the matrix is the space within the inner membrane. The word `` matrix '' stems from the fact that this space is viscous, compared to the relatively aqueous cytoplasm. The mitochondrial matrix contains the mitochondria 's DNA, ribosomes, soluble enzymes, small organic molecules, nucleotide cofactors, and inorganic ions. The enzymes in the matrix facilitate reactions responsible for the production of ATP, such as the citric acid cycle, oxidative phosphorylation, oxidation of pyruvate and the beta oxidation of fatty acids. The composition of the matrix based on its structures and contents produce an environment that allows the anabolic and catabolic pathways to proceed favorably for. The electron transport chain and enzymes in the matrix play a large role in the citric acid cycle and oxidative phosphorylation. The citric acid cycle produces NADH and FADH2 through oxidation that will be reduced in oxidative phosphorylation to produce ATP. The cytosolic, intermembrane space, compartment has a water content of 3.8 μl / mg protein, while the mitochondrial matrix 0.8 μl / mg protein. It is not known how mitochondria maintain osmotic balance across the inner mitochondrial membrane, although the membrane contains aquaporins that are believed to be conduits for regulated water transport. Mitochondrial matrix has a pH of about 7.8. Mitochondrial DNA was discovered by Nash and Margit in 1963. One to many double stranded mainly circular DNA is present in mitochondrial matrix. Mitochondrial DNA is 1 % of total DNA of a cell. It is rich in Guanine and Cytosine content. Mitochondria of mammals have 55s ribosomes. Contents 1 Composition 1.1 Metabolites 1.2 Enzymes 1.3 Inner Membrane Components 1.4 Inner Membrane Control Over Matrix Composition 2 Processes In the Mitochondrial Matrix 2.1 The Citric Acid Cycle 2.2 Oxidative Phosphorylation 2.3 Urea Cycle 2.4 Transamination 2.5 Regulation 2.6 Protein Synthesis 3 See also 4 References Composition Metabolites The matrix is host to a wide variety of metabolites involved in processes within the matrix. The Citric Acid Cycle involves acyl - CoA, Pyruvate, Acetyl - CoA, Citrate, Isocitrate, α - Ketoglutarate, Succinyl - CoA, Fumarate, Succinate, L - Malate, and Oxaloacetate. The Urea Cycle makes use of L - Ornithine, Carbamoyl Phosphate, and L - Citrulline. The electron transport chain oxidizes coenzymes NADH, FADH2. Protein synthesis makes use of mitochondrial DNA, RNA, and tRNA. Regulation of processes makes use of ions ( Ca / K / Mg ). Additional metabolites present in the matrix are CO H O, O ATP, ADP, and P. Enzymes Enzymes from processes that take place in the matrix. The Citric Acid Cycle is facilitated by Pyruvate dehydrogenase, Citrate synthase, Aconitase, Isocitrate dehydrogenase, α - ketoglutarate dehydrogenase, Succinyl - CoA Synthetase, Fumarase, and Malate dehydrogenase. The Urea Cycle is facilitated by Carbamoyl phosphate synthetase I and Ornithine transcarbamylase. β - Oxidation uses pyruvate carboxylase, Acyl - CoA dehydrogenase, and β - Ketothiolase. Amino acid production is facilitated by transaminases. Inner membrane components The inner membrane is a phospholipid bilayer that contains the complexes of oxidative phosphorylation. which contains the electron transport chain that is found on the cristae of the inner membrane and consists of four protein complexes and ATP synthase. These complexes are Protein complex I ( NADH : Coenzyme Q Oxidoreductase ), protein complex II ( Succinate : Coenzyme Q Oxidoreductase ), protein complex III ( Coenzyme Q : Cytochrome C Oxidoreductase ), and protein complex IV ( Cytochrome C Oxidase ). Inner membrane control over matrix composition The electron transport chain is responsible for establishing a pH and electrochemical gradient that facilitates the production of ATP through the pumping of protons. The gradient also provides control of the concentration of ions such as Ca driven by the mitochondrial membrane potential. The membrane only allows nonpolar molecules such as CO and O and small non charged polar molecules such as H O to enter the matrix. Molecules enter and exit the mitochondrial matrix through transport proteins and ion transporters. Molecules are then able to leave the mitochondria through porin. These attributed characteristics allow for control over concentrations of ions and metabolites necessary for regulation and determines the rate of ATP production. Processes in the mitochondrial matrix The citric acid cycle Following glycolysis, the citric acid cycle is activated by the production of acetyl - CoA. The oxidation of pyruvate by Pyruvate dehydrogenase in the matrix produces CO, acetyl - CoA, and NADH. Beta oxidation of fatty acids serves as an alternate catabolic pathway that produces acetyl - CoA, NADH, and FADH. The production of acetyl - CoA begins the citric acid cycle while the co-enzymes produced are used in the electron transport chain. ATP Synthesis as seen from the perspective of the matrix. Conditions produced by the relationships between the catabolic pathways ( Citric Acid Cycle and Oxidative Phosphorylation ) and structural makeup ( Lipid Bilayer and electron transport chain ) of matrix facilitate ATP synthesis. All of the enzymes for the citric acid cycle are in the matrix ( e.g. citrate synthase, iso - citrate dehydrogenas e, alpha - ketoglutarate dehydrogenase, fumarase, and malate dehydrogenase ) except for succinate dehydrogenase which is on the inner membrane and is part of protein complex II in the electron transport chain. The cycle produces coenzymes NADH and FADH through the oxidation of carbons in two cycles. The oxidation of NADH and FADH produces GTP from succinyl - CoA synthetase. Oxidative phosphorylation NADH and FADH2 are produced in the matrix or transported in through porin and transport proteins in order to undergo oxidation through oxidative phosphorylation. NADH and FADH2 undergo oxidation in the electron transport chain by transferring a electron s to regenerate NAD and FAD. Protons are pulled into the intermembrane space by the energy of the electrons going through the electron transport chain. Four electrons are finally accepted by oxygen in the matrix to complete the electron transport chain. The protons return to the mitochondrial matrix through the protein ATP synthase. The energy is used in order to rotate ATP synthase which facilitates the passage of a proton, producing ATP. A pH difference in the matrix and intermembrane space creates an electrochemical gradient by which ATP synthase can pass a proton into the matrix favorably. Urea cycle The first two steps of the Urea Cycle take place within the mitochondrial matrix of liver and kidney cells. In the first step Ammonia is converted into carbamoyl phosphate through the investment of two ATP molecules. This step is facilitated by Carbamoyl phosphate synthetase I. The second step facilitated by Ornithine transcarbamylase converts carbamoyl phosphate and Ornithine into citrulline. After these initial steps the Urea Cycle continues in the inner membrane space until ornithine once again enters the matrix through a transport channel to continue the first to steps within matrix. Transamination α - Ketoglutarate and oxaloacetate can be converted into amino acids within the matrix through the process of transamination. These reactions are facilitated by transaminases in order to produce aspartate and asparagine from oxaloacetate. Transamination of α - ketoglutarate produces glutamate, proline and arginine. These amino acids are then used either within the matrix or transported into the cytosol to produce proteins. Regulation Regulation within the matrix is primarily controlled by ion concentration, metabolite concentration and energy charge. Availability of ions such as Ca control various functions of the Citric Acid Cycle. in the matrix activates pyruvate dehydrogenase, isocitrate dehydrogenase, and alpha - ketoglutarate dehydrogenase which increases the reaction rate in the cycle. Concentration of intermediates and coenzymes in the matrix also increase or decrease the rate of ATP production due to anaplerotic and cataplerotic effects. NADH can act as an inhibitor for α - ketoglutarate, isocitrate dehydrogenase, citrate synthase, and pyruvate dehydrogenase. The concentration of oxaloacetate in particular is kept low, so any fluctuations in this concentrations serve to drive the Citric Acid cycle forward. The production of ATP also serves as a means of regulation by acting as an inhibitor for Isocitrate dehydrogenase, Pyruvate dehydrogenase, the electron transport chain protein complexes, and ATP syntahase. While ADP acts as an activator. Protein synthesis The mitochondria contains its own set of DNA used to produce proteins found in the electron transport chain. The mitochondrial DNA only codes for about thirteen proteins that are used in processing mitochondrial transcripts, ribosomal proteins, ribosomal RNA, transfer RNA, and protein subunits found in the protein complexes of the electron transport chain. See also Matrix ( biology ) Mitochondrial DNA Mitochondrion References ^ Jump up to : Voet, Donald ; Voet, Judith ; Pratt, Charlotte ( 2013 ). Fundamentals of Biochemistry Life at the Molecular Level. New York City : John Wiley & Sons, Inc. pp. 582 -- 584. ISBN 1118129180. ^ Jump up to : Stryer, L ; Berg, J ; Tymoczko, JL ( 2002 ). Biochemistry. San Francisco : W.H. Freeman. pp. 509 -- 527, 569 -- 579, 614 -- 616, 638 -- 641, 732 -- 735, 739 -- 748, 770 -- 773. ISBN 0 - 7167 - 4684 - 0. Jump up ^ Mitchell, Peter ; Moyle, Jennifer ( 1967 - 01 - 14 ). `` Chemiosmotic Hypothesis of Oxidative Phosphorylation ''. Nature. 213 ( 5072 ) : 137 -- 139. doi : 10.1038 / 213137a0. PMID 4291593. ^ Jump up to : Soboll, S ; Scholz, R ; Freisl, M ; Elbers, R ; Heldt, H.W. ( 1976 ). Distribution of metabolites between mitochondria and cytosol of perfused liver. New york : Elsevier. pp. 29 -- 40. ISBN 978 - 0 - 444 - 10925 - 5. ^ Jump up to : Porcelli, Anna Maria ; Ghelli, Anna ; Zanna, Claudia ; Pinton, Paolo ; Rizzuto, Rosario ; Rugolo, Michela ( 2005 - 01 - 28 ). `` pH difference across the outer mitochondrial membrane measured with a green fluorescent protein mutant ''. Biochemical and Biophysical Research Communications. 326 ( 4 ) : 799 -- 804. doi : 10.1016 / j. bbrc. 2004.11. 105. PMID 15607740. ^ Jump up to : Dimroth, P. ; Kaim, G. ; Matthey, U. ( 2000 - 01 - 01 ). `` Crucial role of the membrane potential for ATP synthesis by F ( 1 ) F ( o ) ATP synthases ''. The Journal of Experimental Biology. 203 ( Pt 1 ) : 51 -- 59. ISSN 0022 - 0949. PMID 10600673. ^ Jump up to : Karmen, A. ; Wroblewski, F. ; Ladue, J.S. ( 1955 - 01 - 01 ). `` Transaminase activity in human blood ''. The Journal of Clinical Investigation. 34 ( 1 ) : 126 -- 131. doi : 10.1172 / JCI103055. ISSN 0021 - 9738. PMC 438594. PMID 13221663. Jump up ^ Alberts, Bruce ; Johnson, Alexander ; Lewis, julian ; Roberts, Keith ; Peters, Walter ; Raff, Martin ( 1994 ). Molecular Biology of the Cell. New york : Garland Publishing Inc. ISBN 0 - 8153 - 3218 - 1. Jump up ^ Anderson, S. ; Bankier, A.T. ; Barrell, B.G. ; de Bruijn, M.H.L. ; Coulson, A.R. ; Drouin, J. ; Eperon, I.C. ; Nierlich, D.P. ; Roe, B.A. ( 1981 - 04 - 09 ). `` Sequence and organization of the human mitochondrial genome ''. Nature. 290 ( 5806 ) : 457 -- 465. doi : 10.1038 / 290457a0. PMID 7219534. ^ Jump up to : Iuchi, S. ; Lin, E.C.C. ( 1993 - 07 - 01 ). `` Adaptation of Escherichia coli to redox environments by gene expression ''. Molecular Microbiology. 9 ( 1 ) : 9 -- 15. doi : 10.1111 / j. 1365 - 2958.1993. tb01664. x. ISSN 1365 - 2958. PMID 8412675. Jump up ^ Tuchman, Mendel ; Plante, Robert J. ( 1995 - 01 - 01 ). `` Mutations and polymorphisms in the human ornithine transcarbamylase gene : Mutation update addendum ''. Human Mutation. 5 ( 4 ) : 293 -- 295. doi : 10.1002 / humu. 1380050404. ISSN 1098 - 1004. PMID 7627182. Jump up ^ Kirsch, Jack F. ; Eichele, Gregor ; Ford, Geoffrey C. ; Vincent, Michael G. ; Jansonius, Johan N. ; Gehring, Heinz ; Christen, Philipp ( 1984 - 04 - 15 ). `` Mechanism of action of aspartate aminotransferase proposed on the basis of its spatial structure ''. Journal of Molecular Biology. 174 ( 3 ) : 497 -- 525. doi : 10.1016 / 0022 - 2836 ( 84 ) 90333 - 4. PMID 6143829. Jump up ^ Denton, Richard M. ; Randle, Philip J. ; Bridges, Barbara J. ; Cooper, Ronald H. ; Kerbey, Alan L. ; Pask, Helen T. ; Severson, David L. ; Stansbie, David ; Whitehouse, Susan ( 1975 - 10 - 01 ). `` Regulation of mammalian pyruvate dehydrogenase ''. Molecular and Cellular Biochemistry. 9 ( 1 ) : 27 -- 53. doi : 10.1007 / BF01731731. ISSN 0300 - 8177. PMID 171557. Jump up ^ Fox, Thomas D. ( 2012 - 12 - 01 ). `` Mitochondrial Protein Synthesis, Import, and Assembly ''. Genetics. 192 ( 4 ) : 1203 -- 1234. doi : 10.1534 / genetics. 112.141267. ISSN 0016 - 6731. PMC 3512135. PMID 23212899. Jump up ^ Grivell, L.A. ; Pel, H.J. ( 1994 ). `` Protein synthesis in mitochondria ''. Mol. Biol. Rep. Swammerdam Institute for Life Sciences. 19 : 183 -- 194. doi : 10.1007 / bf00986960. Mitochondrial proteins Outer membrane fatty acid degradation Carnitine palmitoyltransferase I Long - chain - fatty - acid -- CoA ligase tryptophan metabolism Kynureninase monoamine neurotransmitter metabolism Monoamine oxidase Intermembrane space Adenylate kinase Creatine kinase Inner membrane oxidative phosphorylation Coenzyme Q -- cytochrome c reductase Cytochrome c NADH dehydrogenase Succinate dehydrogenase pyrimidine metabolism Dihydroorotate dehydrogenase mitochondrial shuttle Malate - aspartate shuttle Glycerol phosphate shuttle other Glutamate aspartate transporter Glycerol - 3 - phosphate dehydrogenase ATP synthase Carnitine palmitoyltransferase II Uncoupling protein Matrix citric acid cycle Citrate synthase Aconitase Isocitrate dehydrogenase Oxoglutarate dehydrogenase complex Succinyl coenzyme A synthetase Fumarase Malate dehydrogenase anaplerotic reactions Aspartate transaminase Glutamate dehydrogenase Pyruvate dehydrogenase complex urea cycle Carbamoyl phosphate synthetase I Ornithine transcarbamylase N - Acetylglutamate synthase alcohol metabolism ALDH2 PMPCB Other / to be sorted steroidogenesis Cholesterol side - chain cleavage enzyme Steroid 11 - beta - hydroxylase Aldosterone synthase Frataxin Mitochondrial membrane transport protein Mitochondrial permeability transition pore Mitochondrial carrier Mitochondrial DNA Complex I MT - ND1 MT - ND2 MT - ND3 MT - ND4 MT - ND4L MT - ND5 MT - ND6 Complex III MT - CYB Complex IV MT - CO1 MT - CO2 MT - CO3 ATP synthase MT - ATP6 MT - ATP8 tRNA MT - TA MT - TC MT - TD MT - TE MT - TF MT - TG MT - TH MT - TI MT - TK MT - TL1 MT - TL2 MT - TM MT - TN MT - TP MT - TQ MT - TR MT - TS1 MT - TS2 MT - TT MT - TV MT - TW MT - TY see also mitochondrial diseases Retrieved from `` https://en.wikipedia.org/w/index.php?title=Mitochondrial_matrix&oldid=828236107 '' Categories : Cell anatomy Matrices ( biology ) Hidden categories : Articles which use infobox templates with no data rows Talk Contents About Wikipedia Català Čeština Français 日本 語 Polski Русский 中文 Edit links This page was last edited on 1 March 2018, at 10 : 31. 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Question: where is the matrix located in the mitochondria
Answer: within the inner membrane