Intermembrane Space of Mitochondria

Because of channels in the outer membrane of the mitochondria, the content of the intermembrane space is similar to that of the content of the cytoplasm.

As electrons move down the proteins in the electron transport chain, the electrons lose energy to bring H+ ions from the mitochondrial matrix into the intermembrane space. As a concentration gradient of hydrogen ions forms, a protein called ATP synthase harnesses the potential energy of these ions and starts chemiosmosis, where the H+ ions reenter the matrix via this enzyme bound to the cristae (folds of the inner membrane). ADP and a phosphate group are combined to form ATP.

Mitochondrial proteins
Outer membrane

fatty acid degradation (Carnitine palmitoyltransferase I, Long fatty acyl CoA synthetase)

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, 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
B strc: edmb (perx), skel (ctrs), epit, cili, mito, nucl (chro)

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