6. aerobic respiration
No description yet. This curated deck is ready for daily study.
Card preview (18)
link reaction in
mitochondrial matrix
link reaction converts
pyruvate to acetyl co enzyme A
steps of the link reaction
• pyruvate is decarboxylated (1 C is removed to form CO2) • pyruvate is oxidised to form acetate. NAD is reduced to form reduced NAD • Acetate is combined with coenzyme A (CoA) to from acetyl coenzyme A (acetyl CoA) • No ATP is produced in this reaction
products of link reaction for 1 glucose molecule
2 molecules of acetyl coenzyme A (go to krebs cycle) 2 CO2 molecules (waste) 2 molecules of reduce NAD (go to oxidative phosphorylation)
kerbs cycle produces
reduced coenzymes and ATP
kerbs cycle involves a series of
oxidation-reduction reactions
where does krebs cycle take place
in the matrix of the mitochondria
krebs cycle
• acetyl co enzyme A combines with 4 C molecule to produce 6 C molecule • 6 C molecule looses 2 x CO2 and hyrdrogen to give a 4 C molecule (H reduces NAD and FAD) • 1 ATP produced • 4 C molecule can combine with acetly A again
reduced NAD and FAD go to
oxidative phosphorylation
oxidative phosphorylation is the process where
electrons from reduced coenzymes (reduced NAD / FAD) are used to make ATP
oxidative phosphorylation involves the
electron transport chain chemiosmosis
how oxidative phosphorylation works
• reduced NAD / FAD oxidised and H released. H split into protons + and electrons e- • electrons move down electron transport chain (made of electron carriers) loose energy at each carrier • energy used by electron carriers to pump protons from mitochondrial matrix into inter membrane space (space between inner and outer mitochondrial membranes) • concentration of protons higher in the intermembrane space than the mitochondrial matrix = electrochemical gradient • protons move down electrochemical gradient via ATP synthase. drives synthesis of ATP from ADP and Pi (known as chemiosmosis) • mitochondrial matrix at end of transport chain protons, electrons and O2 (from blood) combine to form water. O2 final electron acceptor
stage - glycolysis molecules produced number of ATP molecules produced
2 ATP = 2 ATP molecules 2 reduced NAD = 2x2.5 = 5 ATP molecule total of 7 ATP molecules
stage - link reaction (x2) molecules produced numer of ATP molecules produced
2 reduced NAD = 2x2.5 = 5 ATP molecules
stage - Krebs cycle (x2) molecules produced number of ATP molecules produced
2 ATP 6 reduced NAD = 2.5 x 6 = 15 ATP molecules 2 reduced FAD = 1.5 x 2 = 3 ATP molecules produced total of 20 ATP molecules produced
how do mitochondrial diseases affect ATP production
affect how proteins involved in oxidative phosphorylation or the kreb cyle function, reducting ATP production
mitochondrial diseases may cause
anaerobic repiration to increase = lots of lactate causing muscle fatigue and weakness some lactate will also diffuse into blood stream leading to high lactate concentrations in the blood
substrates other than glucose that can be used in repiration
some products resulting from breakdown of other molecules such as fatty acids from lipids, amino acids from proteins can be converted into molecules that are able to enter the krebs cycle