Chapter 5-4

Question 1

Describe where Methyl Group is passed from THF?

Answer 1

THF–> B12–> Homocysteine–> Methionine

Question 2

Macrocytic anemia commonly due to?

Answer 2

folate and vitamin B12 def. Also alcoholism, liver disease, 5-FU

Question 3

Folate is absorbed where?

Answer 3

jejunum - Takes months to get a def.

Question 4

methotrexate

Answer 4

lead to folate def by inhibiting dihydrofolate reductase

Question 5

Lab findings of folate def?

Answer 5

macrocytic RBCs and hypersegmented neutrophils
Glossitis
Dec Serum folate 
Increase serum homocystene
normal methylmalnoic acid

Question 6

pernicious anemia

Answer 6

most common cause of Vit B12 def bc of automimmune destruction of parietal cells leads to intrinsic factor def.

Question 7

causes of B12 anemia

Answer 7

Pernicious Anemia
Chrons dz
Diphyllobothrium latum- fish tapeworm.
COMMON ONLY IN VEGANS

Question 8

what is Vitamin B12 cofactor for

Answer 8

1- synthesis DNA

2-converts methylmalonic acid to succinyl CoA

Question 9

In b12 anemia what happens to methylmalonic acid

Answer 9

Increased levels of methylmalonic acid (precursor to succinyl CoA) impairs spinal cord myelinization

Question 10

difference in labs between folate and B12 def.

Answer 10

both have increase serum homocysteine but VitB12 has increase methylmalonic acid