Test 4 questions and answers Flashcards
- Indicate the direct carbon donor in the thymidylate synthase reaction?
A) N5,N10-methylene tetrahydrofolate
B) N10-formyl tetrahydrofolate
C) 7,8-dihydrofolate
D) Tetrahydrofolate
A) N5,N10-methylene tetrahydrofolate
- Which amino acid is required for the synthesis of -amino levulinate (ALA) in the heme synthesis pathway?
A) glutamate
B) glutamine
C) glycine
D) alanine
C) glycine
- What is a key regulatory enzyme in heme biosynthesis?
A) Ferrochelatase
B) δ-aminolevulinate synthase 1
C) Protoporphirynogen oxidase
D) Uroporphirynogen decarboxylase
B) δ-aminolevulinate synthase 1 (ALAS1)
- What are the symptoms of congenital erythropoietic porphyria?: [W]
A) photosensitivity
B) increased urinary and fecal uroporphyrin I
C) abdominal pain
D) neuropsychiatric symptoms
A) photosensitivity
B) increased urinary and fecal uroporphyrin I
- In the synthesis of which amino acid is the 3-phosphoglycerate dehydrogenase enzyme
involved?:
A) Alanine
B) Methionine
C) Serine
D) Glycine
C) Serine
- Which of the following amino acids is not broken down to alpha-ketoglutarate?:
A) histidine
B) tryptophan
C) arginine
D) glutamine
B) tryptophan
- Choose amino acids that decompose to fumarate: [W]
A) Tryptophan
B) Phenylalanine
C) Tyrosine
D) Histidine
A) Tryptophan
B) Phenylalanine
C) Tyrosine
- Deficiency of which of the following enzymes is responsible for phenylketonuria?
A) Phenylalanyl aminotransferase
B) Tyrosine hydroxylase
C) Phenylalanyl dehydrogenase
D) Phenylalanine hydroxylase
D) Phenylalanine hydroxylase
- Which animals are ureotelic?
Panda and shark
(land vertebrates + shark)
- What are the products of arginase?
Ornithine and urea
- What do we do in the case of a mutation in argininosuccinate lyase?
We provide arginine
- How many ATP molecules are required for urea synthesis?
3
- The cofactor for all aminotransferases is pyridoxal phosphate (PLP)
Vitamin B6
- What is the intermediate of the urea cycle and Krebs cycle?
Fumarate
- In which disease do we administer allopurinol?
In gout and kidney stones
- Which amino acids are ketogenic?
Leucine and Lysine
- Which amino acids are branched-chain?
Valine, isoleucine and leucine
- In which disease is there an abundance of bilirubin
diglucuronide?
Obstructive jaundice
- The end product of purine degradation is
Uric acid
- Which of the following compounds inhibits glutamate
dehydrogenase?
GTP
- Which of the breakdown products of heme is responsible for giving urine a straw color?
Urobilin
- Deficiency of which enzyme is associated with phenylketonuria?
Phenylalanine hydroxylase
- Which of the listed amino acids does not undergo transamination?
Proline, hydroxyproline, threonine and lysine
- Where do the amino groups in urea come from?
Asparagine and ornithine
- Identify the tissues where arginine synthesis from citrulline occurs
Kidneys and brain
- Identify the dominant amino acids in collagen
Glycine and proline
- In which cellular compartment is glutamate dehydrogenase present?
Mitochondrial matrix
- Which of the following amino acids is not found in proteins?
Homohydroxy carnitine (?), ornithine and citrulline