Fructose-Galactose-Sorbitol Flashcards
Fructose is phosphorylated to fructose-1-phosphate by →
Fructokinase
Fructose-1-phosphate is split into DHAP and glyceraldehyde by →
Aldolase B
Glyceraldehyde is converted to glyceraldehyde-3-phosphate by →
Triose kinase
Galactose is phosphorylated to galactose-1-phosphate by →
Galactokinase
Galactose-1-phosphate and UDP-glucose are converted to glucose-1-phosphate and UDP-galactose by →
Galactose-1-phosphate uridyltransferase
UDP-galactose is converted to UDP-glucose by →
UDP-4-epimerase
Galactose is converted to galactitol by →
Aldose reductase
What enzyme is deficient in essential fructosuria →
Fructokinase
What is the inheritance pattern of essential fructosuria →
Autosomal recessive
Why is fructose not trapped in cells in essential fructosuria →
Fructose is not phosphorylated; hexokinase converts it to fructose-6-phosphate instead
What are the symptoms of essential fructosuria →
Asymptomatic, benign; fructose in blood and urine
What enzyme is deficient in hereditary fructose intolerance →
Aldolase B
What accumulates in hereditary fructose intolerance →
Fructose-1-phosphate
What are the symptoms of hereditary fructose intolerance →
Hypoglycemia, jaundice, vomiting, cirrhosis (after fruit intake)
What should be avoided in hereditary fructose intolerance →
Avoid fructose, sucrose, and sorbitol
What enzyme is deficient in galactokinase deficiency →
Galactokinase
What is the symptom profile of galactokinase deficiency →
Mild; galactosemia, galactosuria, cataracts, social smile delay
What enzyme is deficient in classic galactosemia →
Galactose-1-phosphate uridyltransferase
What causes the damage in classic galactosemia →
Accumulation of galactitol and other toxic substances
What are the symptoms of classic galactosemia →
Failure to thrive, jaundice, hepatomegaly, cataracts, intellectual disability, E. coli sepsis
What is the treatment for classic galactosemia →
Exclude galactose and lactose from diet
