15 Questions
Which of the following is a nonprotein nitrogen-containing compound synthesized from amino acids?
Porphyrins
What is the primary role of the hepatic enzyme phenylalanine hydroxylase (PAH)?
Metabolism of phenylalanine to tyrosine
In which organ is ammonium produced during deamination of amino acids converted into urea?
Liver
Which of the following compounds is necessary to metabolize the amino acid phenylalanine to tyrosine?
Phenylalanine hydroxylase (PAH)
Which genetic disorder is characterized by a deficiency in the hepatic enzyme phenylalanine hydroxylase (PAH)?
Phenylketonuria (PKU)
What percentage of body energy is due to proteins?
12-20%
What is the primary cause of the musty odor in the urine of individuals with PKU?
Presence of phenyllactic acid
In which variant of PKU are phenylalanine levels typically between 600 and 1200 μmol/L?
Mild PKU
What is the rare form of PKU that occurs when there is a defect in the biosynthesis of the cofactor tetrahydrobiopterin (BH4)?
PKU with normal PAH activity
What damage can occur if PKU is left untreated?
Progressive mental retardation
What type of assay is used for screening PKU in infants?
Guthrie bacterial inhibition assay
What is the metabolic antagonist to B. subtilis growth used in the Guthrie bacterial inhibition assay?
$\beta 2$-thienylalanine
At what blood level does the Guthrie bacterial inhibition assay indicate that bacterial growth occurs?
$>$2 mg/dL
What is necessary to avoid false-negative results in the Guthrie bacterial inhibition assay?
$<$24 hours old infant for testing
In which variant of PKU do phenylalanine levels range from 180-600 μmol/L with no accompanying accumulation of phenylketones?
Mild PKU
Test your knowledge of amino acid metabolism and plasma proteins with this quiz. Learn about the synthesis of plasma, intracellular and structural proteins, nonprotein nitrogen containing compounds, and the conversion of ammonium into urea in the liver.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
