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19 Cards in this Set
- Front
- Back
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In what three tissues does gluconeogenesis take place?
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Liver (major), kidney, small intestine
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What two enzymes are used to convert pyruvate to PEP?
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1) Pyruvate carboxylase
(pyruvate -> OAA) 2) PEP carboxykinase (OAA -> PEP) |
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What molecule allosterically activates Pyruvate Carboxylase?
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Acetyl CoA
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What enzyme catalyzes the following gluconeogenic reaction:
Fructose 1,6-bisphosphate -> Fructose 6-phosphate |
Fructose 1,6 bisphosphatase
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Which precursor molecules feed into the first the first gluconeogenic step of converting pyruvate to PEP?
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1) Alanine (glucose-alanine cycle)
2) Lactate (glucose-lactate cycle) 3) Amino Acids *Other AAs enter at different entry points |
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What molecule results from the addition of NH2 to pyruvate?
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Alanine
*This reaction occurs in the muscle during glucose-alanine cycle |
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How many ATP are consumed during gluconeogenesis of 1 glucose molecule?
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6 ATP
*2 ATP generated during glycolysis of 1 glucose molecule |
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Where does the energy come from that drives gluconeogenesis?
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Fatty acid catabolism
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What affect does Acetyl CoA have on the following enzymes:
1) Pyruvate Dehydrogenase? 2) Pyruvate Carboxylase |
1) Inhibition (PDH also inhibited by NADH)
2) Activation *Acetyl CoA is product of FA B-oxidation. Goal now is to make more glucose. |
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What affect does glucagon have on PFK-2?
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Inactivates PFK-2 by phosphorylation via PKA
*This allows Fructose-6-P to be in a higher concentration compared to Fructose-2,6-BP |
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In what three ways is GNG regulated?
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1) Hormonal (glucagon/insulin)
2) Allosteric (ATP and ADP) 3) Substrate availability |
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Which three organs use ketone bodies for energy?
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Muscle, Liver, Brain
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Which adipose tissue enzyme frees fatty acids from TG in response to glucagon and epinephrine?
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Hormone sensitive lipase
*low insulin/glucagon ratio -> cAMP -> PKA -> phosphorylation of HSL -> TG breakdown -> FA into blood bound to albumin -> Liver |
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What are the three lipases found in the body? Where are they located?
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1) Pancreatic Lipase- secreted by pancreas into small intestine
2) Lipoprotein Lipase- lumen of capillaries 3) Hormone Sensitive Lipase- adipose tissue |
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Name the three ketone bodies formed in the liver.
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1) Acetoacetate (4C)
2) B-hydroxybutyrate (4C) 3) Acetone (3C) |
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Why is B-hydroxybutyrate more energy-rich than acetoacetate?
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B-hydroxyacetate is the reduced form of acetoacetate. To be used, it is converted to acetoacetate and forms NADH
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What happens to acetyl CoA formed from fatty acid B-oxidation?
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It is converted to ketone bodies and transported to other tissues
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What is the regulating enzyme in ketone body synthesis?
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HMG-CoA synthetase
*induced during a fast |
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What are the three forms of ketoacidosis?
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1) Diabetic ketoacidosis
2) Alcoholic ketoacidosis 3) Starvation ketoacidosis |
