| Question |
Answer |
| Which AA is the only strictly ketogenic-branched chain amino acid? |
Leu |
| Branched chain amino acids undergo carboxylation to form CoA derivatives via what enzyme? |
alpha-keto acid dehydrogenase |
| What 7 amino acids from Acetyl CoA? |
Leu, Ile, Lys, Tyr, Thr, Phe, Trp |
| What enzyme converts phenylalanine into tyrosine? |
phenylalanine hydroxylase |
| What is a deficiency in the phenylalanine hydroxylase called? |
PKU- phenylketouria |
| What is the fate of the catabolism of Trp? |
Kynurenine, Formate, Alanine, Niacin |
| Saccharopine is an intermediate in catabolism of what AA? |
Lys |
| Genetic abnormalities in saccharopine can lead to what two causes in the blood? |
hyerlysinemia, hyperammonemia |
| What is the chance of PKU in live births? |
1:10,000 |
| Elevated Phe can also lead to what other metabolites being elevated? |
phenylpyruvate, phenylacetate, phenyllactate |
| What are some symptoms of PKU babies? |
delayed psychomotor maturation, tremors, seizures, eczema, hyperactivity |
| Patients with PKU that develop neurological symptoms despite diet restrictions have a deficiency in what enzyme? |
BH2 reductase (DHPR) |
| What 2 things causes malignant hyperphenylalaninemia? |
DHPR deficiency or GTP biosynthesis deficiency |
| What is homocystinuria? |
elevated homocysteine and methionine |
| What is the cause of homocystinuria? |
defect in cystathionine synthase or cystathionase |
| What is the treatment for homocystinuria? |
reduce Met intake and vit B6 |
| What is the cause of Cystinuria? |
defect in the intestinal epithelial transport cells for Cys2, Lys, Arg, Orn |
| What is the TX for Cystinuria? |
increase fluid volume and pH in the urine |
| What is cystinosis? |
a rare disorder caused by defective Cys2 carrier across lysosomal membranes |
| What is the cause of Maple Syrup Urine Disease? |
defect in dehydrogenase that decarboxylates branched-chain AAs (Leu, Ile, Val) |
| What are clinical signs of alcaptonuria? |
darkening of urine on standing in air |
| What causes alcaptonuria? |
lack of homogentisate oxidase involved in the catabolism of Tyr |
| What is significant about tyrosinemias? |
nothing, they are benign |
| What are the 4 known defects in Tyrosine catabolism? |
Type I tyrosinemia |
| What is Kwashiorkor? |
lack of protein in the diet |
| What are symptoms of kwashiorkor? |
muscle wasting, decreased plasma proteins, edema |
| What causes hartnup disease? |
impaired transport of neutral AAs across intestinal and renal epithelial cells |
| What are symptoms of hartnup disease? |
like pellegra (4D's) |
| What 2 AAs are thought to be strictly ketogenic including both branched and non-branched AAs? |
Leu and Lys |
| What is BH4? |
tetrahydrobiopterin |
| What is BH2? |
dihydrobiopterin |
| What AA competitively inhibits liver arginase? What does it cause? |
Lys; hyperammonemia |
| What AA becomes an essential dietary AA with PKU? |
Tyr |
Cardio Block2anatomy
