Glycolysis Flashcards
(58 cards)
What are the 2 types of metabolic pathways?
Catabolic and Anabolic
Which pathway is this?:
-where the energy yielding macromolecules are broken down into simple molecules which will undergo complete breakdown to yield energy poor end products, during this process they will produce energy rich molecules like ATP and NADH+H, FADH2.
Catabolic
Which pathway is this?:
-where the simple molecules either synthesized with in the cells or derived from the diet will combine to form macromolecules. During this process the energy is consumed and the energy required for these pathways will be given by the energy produced by catabolic pathways.
Metabolic
What does one molecule of glucose generate?
2 pyruvate
In general, what is the net yield from glycolysis if the cell has mitochondria?
8 net ATP
What is the net yield from glycolysis under anaerobic conditions?
2 ATP and 2 lactate.
What are the 3 enzymes in glycolysis that catalyze irreversible reactions?
- Hexokinase/glucokinase
- Phosphofructokinase-1
- Pyruvate Kinase
What is the rate-limiting enzyme for glycolysis?
Phosphofructokinase-1
What enzyme catalyzes the only oxidation reduction reaction in glycolysis?
Glyceraldehyde 3-phosphate dehydrogenase
Deficiency of what enzyme leads to hemolytic anemia?
Pyruvate kinase
Which is present in most tissues?
hexokinase
Which is present in hepatocytes and beta-cells of the pancreas?
glucokinase
What is one form of MODY due to?
mutation of the pancreatic glucokinase gene
What are the 2 different gates of pyruvate?
- In nonproliferating cells, in the presence of O2 and mitochondria, pyruvate enters into TCA cycle as acetyl CoA.
- Anaerobic glycolysis: decreased O2 and no mitochondria, pyruvate forms lactate.
What is invested in the energy investment phase of glycolysis?
2 ATPs
What is generated in the energy generation phase of glycolysis?
4 ATPs, 2 NADH, and 2 pyruvate molecules
What enzyme does fluroride inhibit and hence causes a decrease in glycolysis?
enolase
What enzyme catalyzes the substrate level phosphorylation resulting in ATP production at a substrate level and is one of the regulated enzymes?
Pyruvate kinase
how is hemolyctic anemia caused?
-when glycolysis levels decrease, ATP decreases, and RBCs can’t maintain the membrane, so they rupture
What is the glycolysis pathway?
- D-glucose is converted irreversibly to glucose-6-phosphate by hexokinase/glucokinase ->
- glucose-6-P is converted to fructose-6-phosphate by phosphoglucose isomerase ->
- Fructose-6-P is irreversibly converted to Fructose-1,6-bisphosphate by phosphofructokinase ->
- Fructose-1,6-bisphosphate is converted to dihydroxyacetone phosphate by aldolase ->
- dihydroxyacetone phosphate is converted to glyceraldehyde-3-phosphate by triose phosphate isomerase ->
- glyceraldehyde-3-phosphate is converted to 1,3-bisphosphoglycerate by glyceraldehyde-3-phosphate dehydrogenase ->
- 1,3-bisphosphoglycerate is converted to 3-phospoglycerate by phosphoglycerate kinase ->
- 3-phospoglycerate is converted to 2-phosphoglycerate by phosphoglyceromutase ->
- 2-phosphoglycerate is converted to phosphoenol-pyruvate by removal of H2O ->
- phosphoenol-pyruvate is converted to pyruvate by pyruvate kinase
Which has a low km and vmax for glucose?
hexokinase
What acts as a glucose sensor in the maintenance of blood glucose homeostasis?
Glucokinase
What does measuring c-peptide show?
Measuring c-peptide shows the amount of endogenous insulin when exogenous insulin is taken
What are negative allosteric modulators of PFK-1?
ATP and citrate
