Biochemistry

Question 1

3 drugs that can cause vit B9 (folate)?

Answer 1

phenytoin, sulfonamide, methotrexate

Question 2

lab findings for B9 (folate) def?

Answer 2

inc homocystein, but normal methylmalonic acid

Question 3

lab findings for B12 def?

Answer 3

inc homocystein, inc methylmalonic acid

Question 4

what path is associated with infantiele cataracts, failure to track objects or to develop social smile

Answer 4

galactokinase def

Question 5

what 2 enzymes require B12 as cofactors?

Answer 5

1. methylmalonyl-CoA

2. homocysteine methyltransferase (methionine synthase)

Question 6

3 causes for homocystinuria?

Answer 6

1. cystathionine synthase def (MC)
2. dec affinity of cystathionine synthase for pyridoxal phosphate (B6)
3. homocysteine methyltransferase def

Question 7

vit b6 (pyridoxine) is converted to

Answer 7

pyridoxal phosphate (PLP)