Anabolic Pathways Flashcards
What is the main source of fructose?
sucrose - which is ingested and cleaved in the intestine -
Why is fructose metabolized much faster than glucose?
it bypasses the posphofructokinase step in glycolysis (the rate limiting step)
What are the products of fructose catabolism?
1) DHAP - goes to gluconeogenesis/glycolysis
2) glyceraldehyde - used to make glyceraldehyde 3 phosphate- enters the TCA cycle then
When fructose levels are high, what happens?
hexokinase phosphorylates and fructose 6 P enters glycolysis
What is essential fructosuria?
no fructokinase - it is a benign condition where fructose eventually builds up in urine
What is hereditary fructose intolerance?
no aldolase B - phosphorylated fructose is trapped intracellularly (no transporter for phosphorylated sugars)
symptoms= severe hypoglycaemia, vomiting, jaundice, haemorrhage, hepatomegaly, renal dysfunction, hyperuricaemia, and lacticacidaemia
therapy: quick detection and removal of fructose and sucrose from diet
What is the main source of galactose?
lactose
What is the result of galactokinase deficiency?
elevation of
