Which of the following conversion is irreversible
One carbon groups are formed from various sources. Except the formation of methyl-THFA The other one-carbons are interconveible The only way of regeneration of active THFA from methyl-THFA is the methionine synthase reaction.
Formyl THFA to Methenyl-THFA
Methenyl THFA to Methylene-THFA
Methylene THFA to Methyl-THFA
All of the above
Methionine and Cysteine details