Term
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Definition
- a series of reactions associated with mitochondria to produce some ATP and a lot of reduced nucleotides
- AKA the TCA cycle and Krebs cycle (Krebs was knighted and given the Nobel prize for his work on the cycle) |
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Term
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Definition
| Acetyl-CoA + 3 NAD + FAD + GDP + Pi + 2 H20 ----> 2 CO2 + 3 NADH + FADH2 + CoASH + GTP |
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Term
| Mitochondrial ultrastructure |
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Definition
**TCA cycle - Matrix
**Succinate deHase - Cristae M.
** Electron Transport - Cristae M.
**PDH Complex - Inner membrane/matrix |
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Term
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Definition
**- complete oxidation of pyruvate to CO2
- reduction of nucleotide electron carriers
- production of some ATP
- regeneration of OAA |
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Term
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Definition
**- succinate dehydrogenase uses FAD
- pyruvate dehydrogenase, isocitrate dehydrogenase, alpha-ketogluterate dehydrogenase, and malate dehydrogenase all involve NADH |
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Term
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Definition
- decarboxylates pyruvate
- promotes entry of pyruvate into cycle via formation of acetyl-CoA
- Subjected to complex regulation
- complex of three separate enzymes |
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Term
| Pyruvate dehydrogenase complex |
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Definition
kinase phosphorylates serine which inactivates PDH
**phosphorylated serine |
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Term
| mechanism for the oxidative decarboxylation of pyruvate |
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Definition
1. pyruvate loses CO2 and HETPP is formed
2. Hydroxyethyl group is transferred to lipoic acid and oxidized to form acetyl dihydrolipoamide
3. acetyl group is transferred to CoA
4. Dihydrolipoamide is reoxidized |
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Term
| Two modes of regulation of pyruvate dehydrogenase |
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Definition
1. allosteric regulation
2. covalent modification |
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Term
| allosteric regulation of pyruvate dehydrogenase |
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Definition
- inhibited by ATP, acetyl-coA, and NADH
- activated by AMP, CoASH, and NAD |
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Term
| Covalent modification of pyruvate dehydrogenase |
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Definition
**- phosphorylation of E1 (PDH) - inactivation
**- modulate PDH protein kinase |
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Term
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Definition
- allows entry of acetyl units via condensation with oxaloacetate to form citrate
1. regulation
- acetyl-CoA/OAA stimulate
- citrate inhibits
- succinyl-CoA inhibits
- high NADH and ATP ratios inhibit |
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Term
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Definition
- oxidation of isocitrate to alphaketogluterate is accompanied by reduction of NAD and release of CO2
1. regulation is ATP/NADH inhibit
ADP and NAD stimulate
oxalosuccinate is an intermediate |
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Term
| alphaketogluterate dehydrogenase |
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Definition
- oxidation of alpha ketogluterate to succinyl-CoA is accompanied by the reduction of NAD and release of CO2
- succinyl-CoA and NADH inhibit |
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Term
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Definition
** ATP is synthesized via nucleoside diphosphate kinase
- high-energy CoA thioester is cleaved to form succinate
- energy is conserved in substrate level phosphorylation of GDP |
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Term
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Definition
- succinate is oxidized to fumarate introducing a trans double bond
-FAD is reduced to FADH2
1. Regulation
- succinate, ATP and Pi activate
- OAA inhibits |
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Term
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Definition
- the final reaction of the TCA cycle
- oxidized to regenerate oxaloacetate and NAD is reduced to NADH
- forward reaction is not favorable but is pulled forward by the depletion of OAA |
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Term
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Definition
- continues carbohydrate oxidation started in glycolysis all the way from pyruvate to CO2
- oxidation of the other energy-rich carbon substances like acetyl-coa from oxidation of fatty acids
- TCA is amphibolic - supply intermediates for other process
- TCA is anapleurotic - regenerate acetyl-acceptor |
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Term
| cumulative summary for glycolysis/TCA |
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Definition
- both will stop unless oxidized nucleotides are regenerated
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