One Carbon transfer

Question 1

Biotin

Answer 1

transfers carboxyl groups - carboxylation reaction

vitamin B7

Question 2

Tetrahydrofolate THF

Answer 2

transfers methylene, formimino, formyl, methenyl, methyl

folate = vitamin B9

Question 3

Folate - Dihydrofolate - Tetrahydrofolate

Answer 3

Folate - Dihydrofolate:

• NADPH -> NADP+
• enzyme: Dihydrofolate reductase

Dihydrofolate - Tetrahydrofolate:

• NADPH -> NADP+
• enzyme: Dihydrofolate reductase

Question 4

Folate deficinecy

Answer 4

CNS problems

normal diet

Question 5

S-Adenosylmethinine SAM

Answer 5

cells can produce it

not a vitamin

Question 6

Methionine + ATP -> SAM

Answer 6

• 2 Pi

enzyme: methionine adenosyl transferase

Question 7

SAM -> S-adenosyl homocysteine

Answer 7

• CH3

enzyme: Methyl transferase

Question 8

S-adenosyl homocysteine -> Homocysteine

Answer 8

reversible
+H20
-adenosine
enzyme: hydrolase

Question 9

Homocysteine -> Methionine

Answer 9

+N5methylTHF
-THF
enzyme: methionine synthase
prostetic group: vitamin B 12

Question 10

Homocysteine -> Cystathionine

Answer 10

L-serine -> H20
enzyme: CYSTATHIONE B SYNTHASE
reguired vitamin B6

Question 11

Cystathionine -> L-cysteine

Answer 11

H2O -> aKB + NH4+
enzyme: gamma CYSTATHIONASE
requires vitamin B6