<prompt> Which of the following metabolic reactions require vitami B12 but not folate?Conversion of malonic acid to succinic acidConversion of homocysteine to methionineConversion of serine to glycineThymidylate synthesis  <response>: Ref: KDT 6e p588 Conversion of malonic acid to succinic acid requires vitamin B12 but not folate. This reaction is required for myelin formation and deficiency of B12 is responsible for demyelination. 