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17 Cards in this Set
- Front
- Back
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What is gluconeogenesis?
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The anabolic formation of glucose from pyruvate.
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Pyruvate carboxylase
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Pyruvate to oxaloacetate
uses bicarbonate step 1 regulated by acetyl-CoA |
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phosphoenolpyruvate carboxykinase (PEPCK)
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oxaloacetate to phophoenolpyruvate
uses GTP transcriptionally regulated, where gene is turned on by glucagon signal transduction |
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enolase
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phosphoenolpyruvate to 2-phosphoglycerate
opposite reaction in glycolysis (step 9) step 3 |
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phosphoglycerate mutase
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2-phosphoglycerate to 3-phosphoglycerate
opposite of step 8 of glycolysis step 4 |
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phosphoglycerate kinase
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3-phosphoglycerate to 1,3-bisphosphoglycerate
uses ATP opposite of step 7 of glycolysis step 5 |
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glyceraldehyde-3-phosphate dehydrogenase
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1,3-bisphosphoglycerate to glyceraldehyde-3-phophate
uses NADH opposite of step 6 of glycolysis step 6 |
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triose phosphate isomerase
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glyceraldehyde-3-phosphate to dihydroxyacetone phosphate
step 7 |
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aldolase
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dihydroxyacetone phosphate and glyceraldehyde-3-phosphate to fructose-1,6-bisphosphate
step 8 |
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fructose-1,6-bisphosphatase
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fructose-1,6-bisphophate to fructose-6-phosphate
inhibited by AMP and fructose-2,6-bisphosphate |
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glucose-6-phosphate isomerase
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fructose-6-phosphate to glucose-6-phosphate
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glucose-6-phosphatase
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glucose-6-phosphate to glucose
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What are the precursors for gluconeogenesis?
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pyruvate, glyceraldehyde-3-phosphate from TCA, acetyl-CoA
major precursors are lactate and amino acids all precursors must me moved to the liver first |
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What is the Cori cycle?
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Glucose is broken down into lactate in the muscles. The lactate is delivered to the liver and made into glucose with energy from fatty acid catabolism.
There is NO net gain or loss of glucose. |
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Where does gluconeogenesis occur?
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Primarily in the liver, but also in the small intestine and pancreas
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What role does fatty acid breakdown play in gluconeogenesis?
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It provides energy and a substrate in the form of glycerol. Glycerol can be converted to glycerol-3-phosphate by glycerol kinase. THis can then be converted to dihydroxyacetone by glycerol-3-phosphate dehydrogenase and enter gluconeogenesis
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What is a substrate cycle?
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the combination of two reactions where the net reaction is the hydrolysis of ATP
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