Overview Production β-oxidation of odd-numbered fatty acids 2 carbon acetyl-CoA groups removed from chain until there are 5 carbons remaining 5 carbon chain split into 1 acetyl-CoA (2C) + 1 propionyl-CoA (3C) Pathway propionyl-CoA → methylmalonyl-CoA catalyzed by propionyl-CoA carboxylase requires biotin (B7) methylmalonyl-CoA → succinyl-CoA catalyzed by methylmalonyl-CoA mutase requires B12 deficiency of B12 results in a blockage of this step result is ↑↑↑ methylmalonate can cause irreversible neuropathy due to pathologic synthesis of myelin with methylmalonate a means to determine whether a patient with megaloblastic anemia is deficient in folate or B12 methylmalonic aciduria not see in folate deficiencies succinyl-CoA → citric acid cycle can be converted to malate is gluconeogenic exception to rule that fatty acids can be converted to glucose