Carb Metabolism 3 Flashcards
What are the 3 most important precursors for gluconeogenesis?
- lactate
- AAs (mostly alanine)
- glycerol from degradation of TAGs
What are the four unique reactions in gluceoneogensis?
- Pyruvate + CO2 + ATP –> pyruvate carboxylase –> OAA + ADP
- OAA + GTP –> PEP carboxykinase –> PEP + GDP + CO2
- Fruc 1,6 bisphosphate –> fructose 1,6 bisphosphotase –> fruc 6 phos
- Gluc 6 Phosphate –> glucose 6 phosphatase –> glucose
What hormone stimulates gluconeogenesis? What inhibits it?
+ glucagon
- insulin
What 4 enzymes are regulated in gluconeogenesis?
- pyruvate carboxylase
- PEP carboxykinase
- Fructose 1,6 bisphosphatase
- Glucose 6 phosphatase
What regulates pyruvate carboxylase?
+acetyl coA
- insulin
What regulates PEP carboxykinase?
+ glucagon, cAMP
- insulin and AMP
What regulates fruc 1,6 bis phosphatase?
+ citrate
-fruc 2,6 bisphosphate, AMP
What regulates gluc 6 phosphatase?
+glucagon
-insulin
Acetyl CoA has two effects on carb metabolism.. what are they?
- represses glycolysis by inhibiting PDH
2. activates gluconeogenesis by stimulating pyruvate carboxylase
Pts with inborn errors of metabolism such as a mutation in fruc 1,6 bisphosphatase have symptoms of what?
fasting hypoglycemia with metabolic acidosis
In what type of condition would you see fasting hypoglycemia with metabolic acidosis?
inborn errors of metabolism such as a mutation in fruc 1,6 bisphosphatase
Lactose is a heterodimer of what 2 things?
B-galactosyltransferase and a-lactalbumin
The major carbohydrate of human milk, lactose is synthesized from what two things?
UDP-galactose and glucose
NADPH is required for the synthesis of what 4 things?
fatty acids, cholesterol, neurotransmitters, nucleotides
What are the steps of the PPP? draw them out
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