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
QUESTIONS 1 of 2 1 2 Previous Next (M1.BC.15.72) A 3-day-old female infant presents with poor feeding, lethargy, vomiting after feeding, and seizures. Labs revealed ketoacidosis and elevated hydroxypropionic acid levels. Upon administration of parenteral glucose and protein devoid of valine, leucine, methionine, and threonine, and carnitine, the infant began to recover. Which of the following enzymes is most likely deficient in this infant? QID: 106505 Type & Select Correct Answer 1 Branched-chain ketoacid dehydrogenase 40% (126/318) 2 Phenylalanine hydroxylase 7% (22/318) 3 Propionyl-CoA carboxylase 44% (140/318) 4 Cystathionine synthase 3% (11/318) 5 Homogentisate oxidase 3% (11/318) M 2 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept Review Full Topic Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK