Gluconeogenesis Flashcards
T/F: Galactose entry into cells is insulin dependent
False
What enzyme catalyzes the release of galactose from lactose?
Lactase
Epimerization of galactose to glucose reaction
Galactose –> Galactose-1P –> UDP-galactose –> UDP-glucose
What enzyme catalyzes reaction of galactose to galactose-1P?
Galactokinase
What enzyme catalyzes reaction of galactose-1P to UDP-galactose?
Galactose-1P uridylytransferase
What is the function of UDP-glucose 4-epimerase?
Change orientation of hydroxyl group at carbon 4 of UDP-galactose during epimerization to UDP-glucose
Is NAD+ oxidized or reduced during epimerization of galactose to glucose?
Reduced to NADH
What is classic galactosemia caused by?
Accumulation of galactose-1P and galactitol in nerve, lense, liver, and kidney tissue
What can elevated galactitol cause?
Cataracts
Galactokinase deficiency
Causes elevation of galactose in blood and urine
What are the products of digestion of sucrose by sucrase?
Glucose and fructose
What percentage of daily calorie intake in the US is fructose?
Around 10%
What enzymes can phosphorylate fructose?
Hexokinase and fructokinase
Km for hexokinase and fructokinase
Hexokinase has a higher Km for glucose than fructose.
Fructokinase has a lower Km for fructose
Where is fructokinase found?
Liver, kidney, small intestine
What enzyme catalyzed production of fructose-1P?
Fructokinase
Where is the most dietary fructose metabolized?
Liver
What is the function of fructose-1P aldolase?
Split fructose-1P into 2 trioses: dihydroxyacetone phosphate and glyceraldehyde
What enzyme
