<prompt> Which of the following metabolic reactions require vitamin B12 but not folate?Conversion of malonic acid to succinic acidConversion of homocysteine to methionineConversion of serine to glycineThymidylate synthesis  <response>: This reaction is required for myelin formation and deficiency of B12 is responsible for demyelination. Other reactions in question requires THFA in addition to Vit B12. 