matrix - containe enzymes for the krebs cycle and the link reaction, also contains mitochondrial DNA
cristae - projections of the inner membrane which increases the surface area for oxidativephosphorylation
inner mitochondrial membrane - contains electron transport chains and ATPsynthase
outer mitochondrial membrane - separates the contents and outside of the cell, creating perfect conditions for aerobic respiration
intermembrane space - proteins pumped into this space by electrontransport chain
70s ribosome - used for protein synthesis
aerobic respiration:
Glycolysis
Link Reaction
Krebs cycle
Oxidative Phosphorylation (electron transport chain)
ATP releases 30.5 KJ/mol of energy time it is hydrolysed
ADP + P = ATP + H2O = +30.5KJ/mol
Glycolysis
cytoplasm
breakdown of glucose into pyruvate
forms 2 ATP, 2 reduced NAD and 2 pyruvate
Link reaction
matrix
conversion of pyruvate into acetyleCoA
per pyruvate it forms 1 acetyle CoA, 1 reduced NAD and 1 carbon dioxide
Krebs Cycle
matrix
series of reactions starting with acetyle CoA
per acetyle CoA it forms 1 ATP, 3 reduced NAD, 1 reduced FAD and 2 carbon dioxide
Oxidativephosphorylation
inner mitochondrial membrane
transfer of electrons through protons, creating a proton gradient that allows the synthesis of ATP
makes approx 30 ATP and water
Glycolysis steps:
phospholylation - two phosphates, released from the two ATP molecules attach to glucose forming a hexose biphosphate
lysis - destabilises molecule causing it to split into two triose phosphate molecules
phosphorylation - another phosphate is added to the two triose phosphates forming two triose bis-phosphate
two triose bis-phosphates are oxidised by the removal of hydrogen to form two pyruvate.NAD accepts the removed hydrogen's, forming two reduced NADS
Link reaction (oxidative decarboxylation)
pyruvate enters matrix by active transport
(x 2) carbon dioxide is removed (decarboxylation) and diffuses out as a waste product and hydrogen is removed (oxidation)
the hydrogen that was removed is accepted by NAD, which becomes (x 2) reduced NAD
(x 2) pyruvate is catalysed by coenzyme A to form (x 2) acetyle CoA
link reaction
pyruvate = (co-enzymeA) acetyle CoA
releases by product of carbon dioxide
2 reducedNAD (NADH)
Krebs cycle
acetyleCoA (2-carbon) combines with Oxaloacetate (4-carbon) to form citricacid (6-carbon)
citric acid undergoes decarboxylation (removal of co2 x2) and dehydrogenation (removal of hydrogen) this is accepted by NAD to form three molecules of reduced NAD and one molecule of reduced FAD.
one ATP is synthesised by substrate level phosphorylation
oxaloacetate is regenerated to continue the cycle
Difference between NAD and FAD:
NAD accepts one electron and one proton when it is reduced, FAD accepts two protons and two electrons when it is reduced.
NAD participates in all stages of respiration, while FAD only accepts protons and electrons in the Krebs cycle.
NAD results in the synthesis of threeATP molecules, while FAD results in the synthesis of twoATP molecules.
Oxidative phosphorylation
hydrogen is released from reducedNAD and FAD, transferring protons and electrons into the matrix
electrons pass down electron transport chain, releasing energy at each stage
energy used to actively transport protons across the inner membrane, from the matrix to the inter membrane space
accumulation of protons form an electrochemical gradient
protons move back into the matrix through ATP synthase, catalysing conversion of ADP and phosphate into ATP - chemiosmosis
Oxygen is the final electron acceptor, and combines with electrons and protons to form water
aerobic respiration forms approx 34ATP per glucose molecule
substrate level phosphorylation - the production of ATP by the addition of a phosphate to ADP without the use of an electron transport chain