Term
| What do the oxidative pathways form in the HMP Shunt pathway? |
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Definition
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Term
| What do the non-oxidative pathways form in the HMP Shunt pathway? |
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Definition
| The non-oxidative reactions allow five carbon sugars to be converted to six carbon sugars, using reversible reactions |
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Term
| What enzyme transfers two carbons between sugars? And where is it located? |
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Definition
| Tranksketolase-found in the cytoplasm |
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Term
| What cofactor is required by Transketolase? |
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Definition
| thiamine pyrophosphate- thus this can be utilized as a measurement for thiamine deficiency |
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Term
| What enzyme transfers 3 carbons between sugars? And where is it located? |
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Definition
| Transaldolase-located in the cytoplasm |
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Term
| Transaldolase requires what residue at its active site? |
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Definition
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Term
What vitamin deficiency causes these two sets of symptoms...
1)fluid retention-affecting the cardiovascular system
2) pain, paralysis- affecting the nervous system |
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Definition
Thiamine deficiency- causes Beriberi
1) wet beriberi
2) dry beriberi |
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Term
What disease caused from a vitamin deficiency of thiamine? Cause these symptoms...
-Primarily seen in alcoholics
-Alcohol impairs thiamine absorption
-Neuronal dysfunction (lack of energy due to lack of pyruvate dehydrogenase activity) |
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Definition
| Wernicke-Korsakoff syndrome |
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Term
| How can you test for thiamine deficiencies? |
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Definition
| measuring transketolase activity in red blood cells |
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Term
What enzyme does this reaction...
Glucose-6-Phosphate +NADP+ -->
6-Phosphogluconolactone + NADPH |
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Definition
| Glucose-6-Phosphate Dehydrogenase |
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Term
What enzyme does this reaction...
6-Phospho-gluconate + NADP+ -->
Ribulose-5-Phosphate + CO2 + NADPH |
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Definition
| 6-Phospho-gluconate Dehydrogenase (it is an oxidation rxn followed by a decarboxylation) |
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Term
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Definition
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Term
| Is Ru5P a substrate for TK or TA? |
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Definition
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Term
| What enzyme converts Ru5P to X5P? |
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Definition
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Term
| What enzyme converts Ru5P to R5P? |
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Definition
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Term
| Other than Ru5P to X5P, what other rxn has a epimerization? |
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Definition
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Term
| The HMP shunt pathway and glycolysis intersect at what compounds? |
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Definition
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Term
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Definition
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Term
| If the cell requires more R5P than NADPH, what happens? |
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Definition
Use TK and TA to generate R5P from F6P and G3P
Bypass the Oxidative steps
Overall rxn is...
5 G6P + ATP --> 6 R5P + ADP + H+ |
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Term
| What happens if the cell needs equal amounts of NADPH and R5P? |
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Definition
Use only the Oxidative pathway: requiring the enzymes G6PDH and 6-PGDH plus isomerase
Overall rxn:
G6P + 2NADP+ + H2O --> CO2 +R5P + 2NADPH + 2H+ |
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Term
| If the cell requires NADPH, but not R5P, what happens? |
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Definition
In this case, go through the oxidative rxns to form NADPH and Ru5P, then use the non-oxidative rxns and gluconeogenesis to convert Ru5P to glucose.
The overall rxn is:
G6P +12NADP+ + 7H2O --> 6CO2 + 12NADPH + 12H+ + Pi |
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Term
| What happens if the cell requires NADPH and carbons for biosynthesis? |
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Definition
Take G6P through the oxidative rxns to generate NADPH and Ru5P. Then take Ru5P and produce pyruvate by combing TK, TA and glycolysis
Overall rxn is:
3 G6P + 6NADP+ + 5 NAD+ + 5 Pi + 8 ADP -->
5 pyruvate +3 CO2 + 6NADPH +5NADH + 8 ATP +2 H2O + 8 H+ |
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Term
| What pathway requires NADPH? |
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Definition
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Term
| What enzyme found in the mitochondria will do this... convert NADH + NADP+ into NAD+ and NADPH in a reversible reaction? |
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Definition
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Term
| What cells are primarily affected by a G6PDH deficiency? |
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Definition
| red blood cells-since they lack mitochondria which has transhydrogenase |
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Term
| What small peptide found in the red blood cell protects itself from oxidative damage? |
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Definition
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Term
| Glutathione is normally reduced, after being oxidized by an oxidizing agent, it needs to be reduced by what? |
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Definition
| NADPH and the enzyme glutathione reductase |
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Term
| If there is a G6PDH deficiency then... |
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Definition
| the red blood cell membrane is vulnerable to oxidative damage once all the glutathione in the membrane had been oxidized |
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Term
| G6DPH deficiency is what type of genetic disorder and found mostly in what ethnic group? |
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Definition
| It is X-linked and commonly found in people of Middle Eastern descent |
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Term
| When is a G6PDH deficiency seen? |
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Definition
| Only under oxidative stress- Not too many oxidizers in our body. Pt should never take anti-malarial drugs since they are oxidizing agents and the mere presence of these drugs will cause hemolytic anemia. (This disease naturally protects a person from malaria, so similar to sickle-cell anemia). |
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