1C Flashcards
Betaine transfers a _ to _ via _
Betaine is a _ with 3 _
- CH3, THF/B12, methyl transferase
- Glycine, methyls
How is betaine formed
Choline > Aldehyde > betaine
T/F: THF is a carrier of 1C at same oxidational states
False. different oxidational states
THF is reduced _ at C _
- Folic acid
- 5,6,7,8
Folic acid is made of (3)
- Heterocyclic pteridine ring
- PABA
- Glutamate
Activation of folic acid via what enzyme
Dihydrofolate reductase(NADPH)
_ competes with PABA and DHFR
Sulfa drugs/sulfanilamide
T/F: THF carries CO2, alkyl, hydroxymethyl, formyl
False. Not CO2
Main entry to 1C pool is _
N5,N10 methylene THF from gly/ser
T/F: Methyl THF is reversibly interconvertible
False(the only irreversible one)
N5N10 methylene THF > N5 methyl THF via ?(irreversible)
NADPH reductase
Methionine synthase
Homocysteine > methionine using methyl-B12
low met, enough B12 > ?
low met, low B12 > ?
- Methyl B12 forms, methionine synthase active
- Me-B12 doesn’t form, no methionine synthase, THF pool trapped as Me-THF
Me-B12 is induced when methionine level is _
Low
Cysteine formed from
C-skeleton of ser + S of met
