Help
Options
Question
What are two different names for the pentose phosphate pathway?
click to flip
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't know
Question
Where in the cell does the pentose phosphate pathway occur?
Remaining cards (18)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Pentose Pathway
Pentose Phosphate Pathway
| Question | Answer |
|---|---|
| What are two different names for the pentose phosphate pathway? | Hexose monophosphate pathway or 6-phosphogluconate pathway |
| Where in the cell does the pentose phosphate pathway occur? | In the cytosol |
| In which organs does the pentose phosphate pathway take place and what does the created NADPH provide for in each? | The liver, mammary glands, and adipose tissue (FA synthesis) as well as the adrenal cortex, testes, and ovaries (synthesis of steroid hormones), Erythrocytes (glutathione reduction) and WBC/Macrophages (phagocytosis). |
| What is the pentose phosphate pathway? | An alternative method for glucose metabolism, it does NOT create energy |
| What are the important products of the pentose phosphate pathway? | Pentoses, NADPH, and H+ |
| Describe the oxidative phase of the pentose phosphate pathway. | 1) Oxidative phase = irreversible reactions, NADPH and pentose produced, used when nucleotide biosynthesis must take place, enzymes are dehydrogenases. |
| Describe the NonOxidative phase of the pentose phosphate pathway. | Nonoxidative phase = reversible rxns, occur when pentoses arent req'd by cells but glycolytic intermediates are, involves interconversion of sugars resulting in the formation of glycolytic intermediates, enzymes are transketolase (TPP) and transaldolase. |
| Describe the steps in the oxidative phase of the pentose phosphate pathway. | Glucose-6-phosphate -> 6-phosphogluconolactone via G6PD (releasing NADPH and H+), which is then -> 6-phosphogluconate and then-> Ribulose-5-phosphate via 6-phosphogluconate dehydrogenase (releasing NADPH, H+, and CO2) |
| What is the regulatory enzyme of the pentose phosphate pathway? | G6PD |
| Describe the steps in the nonoxidative phase of the pentose phosphate pathway. | If 3 mols of G6P -> 3 mols of Ribulose5P, Ribulose5P -> Ribose5P (via isomerase) + 2 Xyulose5P (via epimerase) -> 2 mols of F6P and 1 Glyceraldehyde-3P (glycolytic intermediates) via transketolase and transaldolase. |
| What is the coenzyme of Transketolase? | TPP (Thiamine) |
| What can be used as a laboratory test to diagnose nutritional thiamine deficiency? | Transketolase activity in RBCs |
| What is Ribose-5-Phosphate required for? | Nucleotide synthesis |
| What are the uses of NADPH? | synthesis of fatty acids, synthesis of steroid hormones, cytochrome p450 system, reduction and detoxification of H2O2, and synthesis of Nitric oxide. |
| What does G6PD deficiency lead to? | Decreased cellular pool of GSH leading to a decrease in detoxification of free radicals/peroxides in cells (accumulate, damage the membrane resulting in hemolysis) as well as protein denaturation (insoluble masses = Heinz bodies) |
| What is the significance of reduce glutathione (GSH)? | It is the major antioxidant in RBCs and it is required for maintenance of SH groups in proteins. |
| In what cell type is G6PD deficiency the most severe? | RBCs because the pentose phosphate pathway is the only means of NADPH generation. |
| What precipitating factors lead to G6PD deficiency? | Infections, oxidant drugs (sulfa drugs, primaquine) and Fava Beans (yes, the vegetable). |
| What is G6PD A- deficiency result in? | A moderate form of the disease, enough young RBCs have sufficient levels of enzyme so they are normally ok but issues arise when exposed to a precipitating factor. |
Created by:
sprater16