Term
| What does the TCA cycle oxidize? |
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Definition
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Term
| What are the major products of 1 round of the TCA cycle starting with 1 acetyl CoA? |
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Definition
| 2 CO2, 1 GTP, 3 NADH, 1 FADH2\ |
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Term
| High energy electrons are produced in the TCA cycle in the form of what? |
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Definition
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Term
| What's a good pneumonic to remember the intermediates of the TCA cycle? |
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Definition
| Officer, Can I Keep Selling Sex For Money? \ |
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Term
| What's the example of substrate level phosphorylation in the TCA cycle? |
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Definition
| Succinate Thiokinase transforms the high-energy thioester of succinyl CoA into GTP\ |
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Term
| Why is the vitamin thiamine important in the TCA cycle? |
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Definition
| TPP, or Thiamine Pyrophosphate(derived from this vitamin), is a important cofactor in the alpha-ketoglutarate dehydrogenase complex\ |
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Term
| What's the first major step of the TCA cycle? |
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Definition
| Oxaloacetate (4 Carbon) is combined with Acetyl CoA (2 Carbon) to produce Citrate (6 Carbon)\ |
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Term
| Something needs to happen to Citrate in order for oxidative decarboxylation to occur in the TCA cycle. What is it? |
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Definition
| Citrate is isomerized to isocitrate, which is then oxidized and decarboxylated to alpha ketoglutarate.\ |
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Term
| What can citrate be used for other than for producing isocitrate? |
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Definition
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Term
| Where is Succinate dehydrogenase located and why is this important? |
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Definition
| It's located in the inner mitochondrial membrane as part of complex I of the electron transport chain - it's used in both the ETC and the TCA cycle\ |
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Term
| What's the purpose of succinate dehydrogenase? |
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Definition
| To generate FADH2 while making fumerate from succinate. In addition, this allows passing of electrons to coenzyme Q in the ETC while bypassing complex I and NOT pumping any Protons\ |
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Term
| What's the purpose of citrate synthase in the TCA cycle? |
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Definition
| to combine oxaloacetate and acetyl CoA to produce Citrate\ |
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Term
| How is Citrate Synthase regulated in the TCA cycle? |
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Definition
| It is product-inhibited by citrate\ |
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Term
| What's the role of isocitrate dehydrogenase in the TCA cycle |
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Definition
| To produce alpha-keto-glutarate, CO2, and NADH from isocitrate\ |
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Term
| Describe the regulation of isocitrate dehydrogenase in the TCA cycle |
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Definition
| Allosterically activated by ADP, inhibited by ATP and NADH\ |
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Term
| Define allosteric activation/inhibition |
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Definition
| Allosteric binding occurs at a site OTHER than the active site, and can lead to enhanced or decreased enzymatic activity at lower substrate concentrations \ |
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Term
| Describe the function of alpha ketoglutarate dehydrogenase in the TCA cycle |
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Definition
| Takes alpha-ketoglutarate and produces succinyl CoA, CO2, and NADH\ |
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Term
| Describe the regulation of alpha ketoglutarate dehydrogenase in the TCA cycle |
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Definition
| alpha-ktoglutarate dehydrogenase is inhibited by ATP, GTP, NADH, and Succinyl CoA\ |
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Term
| Describe the coordination between the TCA cycle and respiratory control |
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Definition
| When ADP is limiting, the respiratory chain slows, slowing oxidation of NADH and FADH2, depleting NAD+ and FAD, and thereby slowing hte TCA cycle\ |
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Term
| Give several function of the TCA cycle |
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Definition
| The TCA cycle is a major catabolic pathway for the generation of ATP, and also is essential for providing intermediates for the biosyntehsis of many compounds\ |
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Term
| Give the amt. of ATP that NADH and FADH2 contribute when converted |
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Definition
| NADH converts to ~2.5 ATP, FADH2 gives ~1.5 ATP\ |
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Term
| How many total ATP are produced when Acetyl CoA is oxidized in the TCA cycle |
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Definition
| 10: 7.5 from NADH, 1.5 from FADH2, and 1 from GTP\ |
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Term
| Where does the TCA cycle take place? |
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Definition
| In the mitochondrial Matrix\ |
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Term
| What are the starting compounds of the TCA cycle |
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Definition
| Oxaloacetate and Acetyl CoA\ |
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Term
| Name a few sources of Acetyl CoA |
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Definition
| Glucose/Pyruvate, Proteins/Amino Acids, Lipids/Fatty Acids, Ketone bodies, ethanol\ |
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Term
| Does the TCA cycle function in Erythrocytes? Why or Why not? |
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Definition
| No - Erythrocytes don't have any mitochondria!\ |
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Term
| Name a few fates of Acetyl CoA |
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Definition
| TCA Cycle (primary), Ketone bodies, Fatty Acids and Sterols\ |
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Term
| Does the TCA cycle use O2? |
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Definition
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Term
| The electron transport chain typically keeps the NAD+/NADH ratio very _______(High or low)? |
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Definition
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Term
| How would blocking the ETC slow the rate of the TCA cycle? |
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Definition
| When the ETC is blocked, NADH builds up and blocks 3 key enzymes in the TCA cycle (isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, and malate dehydrogenase)\ |
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Term
| Why haven't we found many inborn errors in the TCA cycle? |
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Definition
| Because these types of errors would be lethal!\ |
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Term
| How will an uncoupler in the ETC affect the TCA cycle |
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Definition
| Uncoupler will cause more Acetyl CoA to enter into the TCA cycle, thereby activating it\ |
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Term
| What are 4 vitamin requirements of the TCA cycle |
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Definition
| Riboflavin, Niacin, Thiamine, and Pantothenic Acid\ |
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Term
| Why is Riboflavin important in the TCA cycle? |
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Definition
| = Vitamin B2, It's part of FAD\ |
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Term
| Why is Niacin important in the TCA cycle |
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Definition
| = Vitamin B3, It's part of NAD+\ |
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Term
| Why is Thiamine important in the TCA cycle? |
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Definition
| = Vitamin B1, It's important at the active site for alpha-keto-dehydrogenase\ |
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Term
| Why is Pantothenic Acid important in the TCA cycle? |
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Definition
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Term
| How will a non-lethal dose of CN affect flux through the TCA cycle? |
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Definition
| it will decrease flux of CoA into the TCA cycle\ |
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Term
| How does the uncoupling of the ETC from ATP synthase affect the flow of electrons to O2? |
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Definition
| It increases the flow of electrons to O2\ |
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Term
| Isocitrate catalyzes what type of reaction |
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Definition
| oxidative decarboxylation |
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Term
| A diet deficient in what vitamin would most directly affect the reaction catalyzed by isocitrate dehydrogenase? |
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Definition
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Term
| Deficiency in what nutrient might lead to lethargy in a 53 year old man w/ history of alcoholism? |
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Definition
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Term
| How does exercise increase flux through the TCA cycle most directly? |
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Definition
| Via increased NAD+/NADH ratios\ |
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Term
| What's the primary role in catabolic metabolism of the TCA cycle? |
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Definition
| To transfer electrons from carbon to NAD+ and FAD\ |
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Term
| How many inches of snow, by Snowbird's measuring standards, does it take to merit skipping class altogether and heading up to the mountain for the day? |
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Definition
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