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15 Cards in this Set
- Front
- Back
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Where is HMP active?
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-In tissues that regularly synthesize steroids or fatty acids.
-eg. mammary tissue, liver, adrenal glands. |
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Fxn's of NADPH?
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-Pyridine nucleotide used for reductive biosynthesis.
-Maintain proper glutathione levels. -VERY ACTIVE IN RBC's. |
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Need for Ribose-5-phosphate?
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-For biosynthesis of ribonucleotides and derivatives.
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Iron Hemoglobin maintained in reduced form (Fe++) through?
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-Action of methemoglobin reductase which requires NADH.... NOT NADPH.
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What are the 2 sections of HMP?
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-Oxidative(regulated part)
-Non-oxidative. |
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Describe the oxidative pathway?
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-3 rxn's.
-All allosterically controled by NADPH -From glucose-6-phosphate to ribulose-5-phosphate, CO2 and 2 NADPH. -ALL INTERMEDIATES ARE PHOSPHORLYATED. |
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Rxn 1 of oxidative pathway?
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- Glucose-6-phosphate--> 6-phosphocluconolactone.
- 1 NADPH(Inhibited by) - Via GLUCOSE-6-PHOSPHATE DEHYGROGENASE |
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Rxn 2 of oxidative pathway?
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- 6-phosphocluconolactone --> 6-Phosphogluconate
- H2O-->H+ - Via Gluconolactonase |
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Rxn 3 of oxidative pathway?
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- 6-Phosphogluconate --> Ribulose-5-Phosphate (first pentose formed)
- 1 NADPH(Inhibited by)& CO2 - Via 6-phosph-gluconate dehydrogenase. |
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Non-oxidative pathway consists of?
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- Near equilibrium rxns.
- Transketolase's - Transaldolase's - Convert Pentose to 3,4,6,7 -carbon sugar phosphates |
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Action of Transketolases?
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***TRANSFER OF 2 CARBON SUGAR***
- Eg. Convert from 5,5 to 3 & 7 sugar phosphate. - REQUIRES TTP |
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What is TPP?
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- Thiamin pyrophosphate
- Covalently bound to enzyme via Schiff Base. (Lysine residue) - Required by TransKetolases. |
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*********Does the phosphate group move throughout the pathway?********
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- NO, the phosphate does not move. The group that bares the phosphate actually moves.
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Action of Transaldolases?
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***TRANSFER OF 3 CARBON SUGAR***
- Eg. 7,3 to 4,6 |
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What are the 2 fates of Rubulose-5-phosphate? Via?
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- Xylulose-5-phosphate via Epimerization
- Ribose-5-phosphate via Isomerization |
