nemoci-sympt/METABOLISMUS/mitochondrie/metabolizmus/dychaci-retezec
Buněčné dýchání a syntéza ATP
- Převážná část buněčného dýchání
- Rozklad různých organických látek
- Výchozí látkou jsou zejména pyruvát a mastné kyseliny
- Vzniká acetylkoenzym A
- Následně vstupuje do Krebsova cyklu
- Redukce koenzymů
- NAD+ na NADH
- FAD na FADH2 [3]
- Elektrony z těchto koenzymů jsou předávány do dýchacího řetězce
- Umístěn na vnitřní membráně mitochondrie [3]
- Dýchací řetězec
- Respiratory chain (RC) - oxidative phosphorylation (OXPHOS)
- 4 multiheteromeric RC complexes, CI–IV
- Transfer the electrons stripped off from nutrient-derived substrates as hydrogen atoms, to molecular oxygen
- Electrons are conveyed to the RC through redox shuttle moieties
- NADH + H+ for complex I
- FADH2 for complex II
- Electron flow is coupled with the translocation of protons across the inner mitochondrial membrane
- From the matrix to the intermembrane space
- Operated by complexes I, III and IV
- Generating an electrochemical gradient
- Exploited by RC complex V (or ATP synthase) - ADP and Pi into ATP
- Numerous specific assembly factors and chaperons are needed to
- Assemble the protein backbone
- Insert suitable prosthetic groups
- Insert metal-containing reactive centers
- Form each holocomplex [9]
Buněčné dýchání a syntéza ATP
- Převážná část buněčného dýchání
- Rozklad různých organických látek
- Výchozí látkou jsou zejména pyruvát a mastné kyseliny
- Vzniká acetylkoenzym A
- Následně vstupuje do Krebsova cyklu
- Redukce koenzymů
- NAD+ na NADH
- FAD na FADH2 [3]
- Elektrony z těchto koenzymů jsou předávány do dýchacího řetězce
- Umístěn na vnitřní membráně mitochondrie [3]
- Dýchací řetězec
- Respiratory chain (RC) - oxidative phosphorylation (OXPHOS)
- 4 multiheteromeric RC complexes, CI–IV
- Transfer the electrons stripped off from nutrient-derived substrates as hydrogen atoms, to molecular oxygen
- Electrons are conveyed to the RC through redox shuttle moieties
- NADH + H+ for complex I
- FADH2 for complex II
- Electron flow is coupled with the translocation of protons across the inner mitochondrial membrane
- From the matrix to the intermembrane space
- Operated by complexes I, III and IV
- Generating an electrochemical gradient
- Exploited by RC complex V (or ATP synthase) - ADP and Pi into ATP
- Numerous specific assembly factors and chaperons are needed to
- Assemble the protein backbone
- Insert suitable prosthetic groups
- Insert metal-containing reactive centers
- Form each holocomplex [9]
Complex I (NADH-ubiquinone oxidoreductase)
- 7 mtDNA-encoded subunits
- ND1–ND6 and ND4L
- At least 37 nucleus-encoded subunits of complex I
- Electrons are transferred from
- NADH, the main redox shuttle of pyruvate dehydrogenase [9]
- TCA cycle
- Onto a hydrophobic mobile electron carrier, ubiquinone (coenzyme Q, CoQ) [9]
Complex I (NADH-ubiquinone oxidoreductase)
- 7 mtDNA-encoded subunits
- ND1–ND6 and ND4L
- At least 37 nucleus-encoded subunits of complex I
- Electrons are transferred from
- NADH, the main redox shuttle of pyruvate dehydrogenase [9]
- TCA cycle
- Onto a hydrophobic mobile electron carrier, ubiquinone (coenzyme Q, CoQ) [9]
Complex II (succinate-ubiquinone oxidoreductase)
- Composed of 4 subunits
- All encoded by the nuclear genome [9]
- Transfers electrons from FADH2
- Mainly derived from beta-oxidation of fatty acids [9]
- To CoQ [9]
Complex II (succinate-ubiquinone oxidoreductase)
- Composed of 4 subunits
- All encoded by the nuclear genome [9]
- Transfers electrons from FADH2
- Mainly derived from beta-oxidation of fatty acids [9]
- To CoQ [9]
Koenzym Q
Koenzym Q
Complex III (ubiquinol-ferricytochrome c oxidoreductase)
- Single mtDNA-encoded subunit
- Apocytochrome b
- 10 subunits encoded by the nuclear genome
- Complex III transfers electrons from:
- CoQ
- To another electron shuttle:
- Cytochrome c [9]
Complex III (ubiquinol-ferricytochrome c oxidoreductase)
- Single mtDNA-encoded subunit
- Apocytochrome b
- 10 subunits encoded by the nuclear genome
- Complex III transfers electrons from:
- CoQ
- To another electron shuttle:
- Cytochrome c [9]
Cytochrom C
- From: coplex III
- To: complex IV [9]
Cytochrom C
- From: coplex III
- To: complex IV [9]
Complex IV (cytochrome c oxidase, COX)
- 3 mtDNA-encoded subunits
- 11 nucleus-encoded subunits
- Transfers electrons to:
- Molecular oxygen
- Formation of water [9]
Complex IV (cytochrome c oxidase, COX)
- 3 mtDNA-encoded subunits
- 11 nucleus-encoded subunits
- Transfers electrons to:
- Molecular oxygen
- Formation of water [9]
Complex V (oligomycin-sensitive ATP synthase)
- Utilizes the energy potential of the electrochemical gradient
- ATP synthesis
- 2 mtDNA-encoded subunits
- ATPase 6 and 8 [9]
- At least 13 nuclear DNA-encoded subunits
- Form 2 distinct particles:
- Membrane-embedded F0 particle
- Rotor operated by protons flowing through it
- Rotation of this structure is transmitted to the matrix-protruding F1 particle [9]
- F1 particle
- Catalyzes the biosynthesis of ATP [9]
Complex V (oligomycin-sensitive ATP synthase)
- Utilizes the energy potential of the electrochemical gradient
- ATP synthesis
- 2 mtDNA-encoded subunits
- ATPase 6 and 8 [9]
- At least 13 nuclear DNA-encoded subunits
- Form 2 distinct particles:
- Membrane-embedded F0 particle
- Rotor operated by protons flowing through it
- Rotation of this structure is transmitted to the matrix-protruding F1 particle [9]
- F1 particle
- Catalyzes the biosynthesis of ATP [9]
