Mention the important series of events of aerobic respiration that occur in the matrix of the mitochondrion as well as one that take place in one membrane of the mitochondrion.
Mention the important series of events of aerobic respiration that occur in the matrix of the mitochondrion as well as one that take place in one membrane of the mitochondrion.
Krebs' cycle occurs in the matrix of mitocondria. ft is depicted in Uie following series of reactions
Electron transport chain is carried out in the inner mitochondria membrane
The inner mitochondria membrane is specific about possessing proton (H+) and electron (e−) acceptors in a particular sequence called electron transport chain. It has four enzyme complexes.
The electrons either follow the pathway of complexes I, III and IV or II, III and IV depending upon the substrates from Krebs` cycle.
The transfer of electrons and hydrogen atoms takes place in the following way Complex I Consists of flavoproteins of NADH dehydrogenase (FPN) of which FMN is the prosthetic group. Combined with the fiavoprotein is non-heme iron of NADH dehydrogenase. This complex spans Inner mitochondrial membrane and is able to translocate protons across it from matrix side to outer side.
Complex II Consists of flavoprotein of succinate dehydrogenase, of which FAD is the prosthetic group. Combined with the flavoprotein is non-heme iron of succinate dehydrogenase.
Between completes II and III is the mobile carrier coenzyme-0 (Co-Q) or ubiquinone (UQ)
Complex III Consists of cytochrorne-b and cylochrome-C1. Associated with cylochrome- b is non-hems iron of complex III. Between complex. III and IV is the mobile carrier cytochrome-c.
Complex IV Consists of cylochrome. anti cytochrome- a3, and bound copper that are required for this complex reaction to occur. This cylochrome also called cytochrome oxidaSe, is the only electron carrier in which the heme iron has a free ligand that can react directly with molecular oxygen.
Thus, hydride ions are transferred from the substance to be oxidised to NAD+ From NAD+ the hydrogen atoms are transferred to FMN of flavoprotein 1 (Fp'N). After FMN the hydrogen atom undergoes ionisation, i.e., it splits into an electron and a proton.
In further stages there is no bnger a transfer .of hydrogens but of electrons. The electron passes to coenzyme- Q. and born coenzyme Ate cytochromes- b, c1, c. a and a_3. The proton is released free,
As the hydrogen atom Of electron passes down by FO−F1, particle the chain, there is simultaneous oxidation of one coenzyme and reduction at another steps. Oxygen is able to diffuse indside the mitochondria.
It is converted to anionic form O−2, combines with 2H+. and forms metabolic water reduced coenzyme NADH+H+. helps in pusing out three pairs of OH+ to outer chamber while FADH2 sends two pairs of H. to outer chamber.
Oxidative phosphorylation is the synthesis of energy rich ATP molecules, with the help of energy liberated during oxidation of reduced coenzyme (NADH2,FADH2) produced in respiration. The enzyme required for this synthesis is called ATP synthase present in inner mitochondria membrane.
The following figures shows this process
Krebs' cycle occurs in the matrix of mitocondria. ft is depicted in Uie following series of reactions
Electron transport chain is carried out in the inner mitochondria membrane
The inner mitochondria membrane is specific about possessing proton (H+) and electron (e−) acceptors in a particular sequence called electron transport chain. It has four enzyme complexes.
The electrons either follow the pathway of complexes I, III and IV or II, III and IV depending upon the substrates from Krebs` cycle.
The transfer of electrons and hydrogen atoms takes place in the following way Complex I Consists of flavoproteins of NADH dehydrogenase (FPN) of which FMN is the prosthetic group. Combined with the fiavoprotein is non-heme iron of NADH dehydrogenase. This complex spans Inner mitochondrial membrane and is able to translocate protons across it from matrix side to outer side.
Complex II Consists of flavoprotein of succinate dehydrogenase, of which FAD is the prosthetic group. Combined with the flavoprotein is non-heme iron of succinate dehydrogenase.
Between completes II and III is the mobile carrier coenzyme-0 (Co-Q) or ubiquinone (UQ)
Complex III Consists of cytochrorne-b and cylochrome-C1. Associated with cylochrome- b is non-hems iron of complex III. Between complex. III and IV is the mobile carrier cytochrome-c.
Complex IV Consists of cylochrome. anti cytochrome- a3, and bound copper that are required for this complex reaction to occur. This cylochrome also called cytochrome oxidaSe, is the only electron carrier in which the heme iron has a free ligand that can react directly with molecular oxygen.
Thus, hydride ions are transferred from the substance to be oxidised to NAD+ From NAD+ the hydrogen atoms are transferred to FMN of flavoprotein 1 (Fp'N). After FMN the hydrogen atom undergoes ionisation, i.e., it splits into an electron and a proton.
In further stages there is no bnger a transfer .of hydrogens but of electrons. The electron passes to coenzyme- Q. and born coenzyme Ate cytochromes- b, c1, c. a and a_3. The proton is released free,
As the hydrogen atom Of electron passes down by FO−F1, particle the chain, there is simultaneous oxidation of one coenzyme and reduction at another steps. Oxygen is able to diffuse indside the mitochondria.
It is converted to anionic form O−2, combines with 2H+. and forms metabolic water reduced coenzyme NADH+H+. helps in pusing out three pairs of OH+ to outer chamber while FADH2 sends two pairs of H. to outer chamber.
Oxidative phosphorylation is the synthesis of energy rich ATP molecules, with the help of energy liberated during oxidation of reduced coenzyme (NADH2,FADH2) produced in respiration. The enzyme required for this synthesis is called ATP synthase present in inner mitochondria membrane.
The following figures shows this process
