Term
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Definition
| generates atp for us in various energy requiring processes in cells and provides various glycolytic intermediates that are used as precursors for biosynthesis of other biomolecules |
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Term
| Where are the 3 control points and what is so special about them? |
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Definition
| Phosphofructokinase, Hexokinase, and Pyruvate kinase. Under the right physiological conditions, these reactions will be effectively irreversible. Also each reaction can be modulated by the binding of allosteric effectors. |
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Term
| Phosphofructokinase does what? |
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Definition
| Fructose 6-phosphate + ATP --> Fructose 1,6-biphosphate + ADP |
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Term
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Definition
| Glucose + ATP --> glucose 6-phosphate + ADP |
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Term
| Pyruvate kinase does what? |
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Definition
| Phosphoenol pyruvate + ADP --> pyruvate + ATP |
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Term
| What serves as a signal for a low energy state in the cell? |
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Definition
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Term
| What reflects the energy charge of the cell? |
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Definition
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Term
| What is the most important control point in mammalian glycolysis? |
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Definition
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Term
| Describe the phosphofructokinase enzyme |
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Definition
| A tetrameric enzyme which has 4 catalytic sites and 4 regulatory sites. T and R states have respectively, lower and higher affinities for F6P. Binds F6P with positive cooperativity |
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Term
| ATP is what kind of regulator and for what? Where does it bind? What does it stabilize? which lowers the affinity of the enzyme for what? |
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Definition
| negative regulator for PFK, regulatory site/allosteric site, and stabilizes the T-state, lowers affinity for F6P |
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Term
| What is the positive regulator of PFK? What does it compete with and for what? What does it do that the negative regulator doesn? basically what is its function |
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Definition
| a positive regulator for PFK, competes with ATP for binding to the allosteric regulatory site, doesn't induce conformational change( which reduces affinity for F6P) - stabilizes the R state; reverses the inhibitory effect of ATP |
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Term
| Describe the hexokinase enzyme |
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Definition
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Term
| What is the negative regulator of HK? |
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Definition
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Term
| The activity of _____ is coupled to the activity of ______ |
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Definition
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Term
| High concentrations of ___ inhibit PFK activity |
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Definition
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Term
| If there is an overaccumulation of fructose 6 phosphate, it is in reverse equilibrium with _____ via which reaction? |
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Definition
| glucose 6 phosphate; via the phosphoglucose isomerase reaction |
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Term
| When the concentration of fructose 6-phosphate increases..the concentration of what subsequently increases? |
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Definition
| glucose 6-phosphate also increases |
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Term
| high concentrations of _____ inhibit hexokinase |
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Definition
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Term
| Describe the pyruvate kinase |
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Definition
| its a homotetrameric enzyme. its R state and T state respectively have higher and lower affinities for PhosphoEnol Pyruvate. |
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Term
| What binds to PK at its allosteric regulatory site to inhibit its activity |
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Definition
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Term
| What is the positive regulator of Pyruvate Kinase? and how does it regulate PK? |
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Definition
| F16BP, binds to allosteric site - induces conformational change which increases affinity of catalytic site for phosphoenol pyruvate (stabilizes R state) |
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Term
| High concentrations of _____ increase pyruvate kinase activity; thus the activity of pyruvate kinase is coupled to the activity of |
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Definition
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Term
| What is the first committed step in the glycolysis pathway? |
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Definition
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Term
| Which step needs NAD+ in the glycolysis pathway? |
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Definition
| Glyceraldehyde 3 phosphate dehydrogenase |
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Term
| HK, PGI, PFK, ALD, TPI, GPD, PGK, PGM, ENO, PK |
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Definition
| hexokinase, phosphate glucose isomerase, phosphofructokinase, aldolase, triose phosphate isomerase, glyceraldehyde 3 phosphate dehydrogenase, phosphoglycerate kinase, phosphoglycerate mutase, enolase, pyruvate kinase |
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