Test 4 questions and answers Flashcards
1
Q
- 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
A) N5,N10-methylene tetrahydrofolate
2
Q
- 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
A
C) glycine
3
Q
- What is a key regulatory enzyme in heme biosynthesis?
A) Ferrochelatase
B) δ-aminolevulinate synthase 1
C) Protoporphirynogen oxidase
D) Uroporphirynogen decarboxylase
A
B) δ-aminolevulinate synthase 1 (ALAS1)
4
Q
- 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
A) photosensitivity
B) increased urinary and fecal uroporphyrin I
5
Q
- In the synthesis of which amino acid is the 3-phosphoglycerate dehydrogenase enzyme
involved?:
A) Alanine
B) Methionine
C) Serine
D) Glycine
A
C) Serine
6
Q
- Which of the following amino acids is not broken down to alpha-ketoglutarate?:
A) histidine
B) tryptophan
C) arginine
D) glutamine
A
B) tryptophan
7
Q
- Choose amino acids that decompose to fumarate: [W]
A) Tryptophan
B) Phenylalanine
C) Tyrosine
D) Histidine
A
A) Tryptophan
B) Phenylalanine
C) Tyrosine
8
Q
- Deficiency of which of the following enzymes is responsible for phenylketonuria?
A) Phenylalanyl aminotransferase
B) Tyrosine hydroxylase
C) Phenylalanyl dehydrogenase
D) Phenylalanine hydroxylase
A
D) Phenylalanine hydroxylase
9
Q
- Which animals are ureotelic?
A
Panda and shark
(land vertebrates + shark)
10
Q
- What are the products of arginase?
A
Ornithine and urea
11
Q
- What do we do in the case of a mutation in argininosuccinate lyase?
A
We provide arginine
12
Q
- How many ATP molecules are required for urea synthesis?
A
3
13
Q
- The cofactor for all aminotransferases is pyridoxal phosphate (PLP)
A
Vitamin B6
14
Q
- What is the intermediate of the urea cycle and Krebs cycle?
A
Fumarate
15
Q
- In which disease do we administer allopurinol?
A
In gout and kidney stones
16
Q
- Which amino acids are ketogenic?
A
Leucine and Lysine
17
Q
- Which amino acids are branched-chain?
A
Valine, isoleucine and leucine
18
Q
- In which disease is there an abundance of bilirubin
diglucuronide?
A
Obstructive jaundice
19
Q
- The end product of purine degradation is
A
Uric acid
20
Q
- Which of the following compounds inhibits glutamate
dehydrogenase?
A
GTP
21
Q
- Which of the breakdown products of heme is responsible for giving urine a straw color?
A
Urobilin
22
Q
- Deficiency of which enzyme is associated with phenylketonuria?
A
Phenylalanine hydroxylase
23
Q
- Which of the listed amino acids does not undergo transamination?
A
Proline, hydroxyproline, threonine and lysine
24
Q
- Where do the amino groups in urea come from?
A
Asparagine and ornithine
25
17. Identify the tissues where arginine synthesis from citrulline occurs
Kidneys and brain
26
18. Identify the dominant amino acids in collagen
Glycine and proline
27
19. In which cellular compartment is glutamate dehydrogenase present?
Mitochondrial matrix
28
20. Which of the following amino acids is not found in proteins?
Homohydroxy carnitine (?), ornithine and citrulline
29
21. Which amino acid is synthesized by the Baranowski enzyme?
Serine
30
22. What is the final product of purine degradation in Dalmatians?
Uric acid
31
23. Identify the direct carbon donor in the synthesis of
thymidylate?
N5N10-methylenetetrahydrofolate
32
24. Which of the amino acids is not degraded to alpha-ketoglutarate?
Tryptophan
33
25. Xanthylate is formed during the reactions leading to the
formation of
GMP
34
26. Choose the amino acids that are broken down to fumarate
Tyrosine and phenylalanine
35
27. Which of the indicated amino acids is ketogenic?
Leucine and lysine
36
28. Which of the following amino acids is used for transporting
amino groups from working muscles?
Alanine
37
29. Propose measures to alleviate the consequences of
argininosuccinate lyase mutations
Reduce protein intake and administer arginine
38
30. In what form are the amino groups of amino acids excreted by
uricotelic organisms?
Uric acid
39
31. Which of the listed amino acids does not undergo
transamination?
Lysine, proline, threonine and hydroxyproline
40
32. Which of the listed amino acids are classified as ketogenic amino acids?
Lysine and leucine.
41
33. Into which of the listed compounds is phenylalanine degraded, among others?
Acetoacetate and fumarate
42
34. What is the name of the enzyme involved in the removal of
α-amino groups from serine?
Serine dehydratase
43
35. What is the name of the enzyme that catalyzes the conversion
of biliverdin to bilirubin?
Biliverdin reductase
44
36. Which of the listed amino acids are involved in the synthesis
of the pyrimidine ring?
Glutamine and asparagine
45
37. Amino acids in the synthesis of the purine ring?
Glycine, asparagine and glutamine.
46
38. Which of the listed compounds is an allosteric activator of
carbamoyl phosphate synthetase II (CPS II)?
PRPP (5-phosphoribosyl-1 pyrophosphate)
{inhibited by CTP}
47
39. What is the molecule that allows the conversion of PRPP to IMP in the salvage pathway?
Hypoxanthine
48
40. Which of the listed compounds serves as a transport form of
nitrogen from muscles to the liver?
Glutamine and alanine
49
41. What is the compound that is the end product of purine catabolism in primates? Provide the name of the enzyme that catalyzes the reaction leading to the formation of this compound
Uric acid and xanthine oxidase
50
42. Complete the sentence: The urea cycle is connected to the (......) through the production of
fumarate by the enzyme (......).
Krebs cycle/ citric acid cycle
argininosuccinate lyase
51
43. Besides ammonium ion and carbon dioxide, what compound is thymine degraded into?
Beta-aminoisobutyric acid
52
44. Porphyrins are heterocyclic compounds consisting of four
(......) rings connected by (......) bridges
pyrrole
methylene
53
45. Provide the full names of two aminotransferases whose activity measurement is used in laboratory diagnostics. What is the name of the coenzyme essential for their activity?
Alanine aminotransferase (ALT), aspartate aminotransferase (AST) and pyridoxal phosphate
54
46. Provide the names of the compounds from which the
synthesis of cysteine begins.
Homocysteine and serine
55
47. Provide the names of all the active one-carbon groups carried by tetrahydrofolate
Methyl, methylene, methenyl, formyl and formimino
56
48. What compound is the primary source of ammonia/ammonium ions that enter the urea cycle?
- Glutamine
57
49. AMP degradation begins with the removal of the (......)
group, leading to the formation of (......).
amino
IMP
58
50. In what form are the amino groups of amino acids excreted by ureotelic organisms?
Urea
59
51. Which of the listed amino acids is exclusively formed by the
action of specific aminotransferases?
Aspartic acid/asparagine
(AST) and alanine (ALT) (aminotransferase abbreviations)
60
52. Provide the names of the products of the major pathway of
glycine degradation in mammals
Carbon dioxide, ammonia and methylenetetrahydrofolate (N5,N10-methyleno-THF)
61
53. Into which of the listed compounds is valine degraded?
Succinyl-CoA
62
54. What is the name of the enzymatic system that catalyzes the
degradation of heme to biliverdin?
Heme oxygenase
63
55. Provide the name of one of the heme proteins responsible for
electron transport in the respiratory chain
Cytochrome C
64
56. What nucleotide is formed in the salvage pathway when
hypoxanthine is attached to PRPP?
Inosine monophosphate
(IMP).
65
57. What is the final product of purine catabolism in non-primate
mammals? Provide the name of the enzyme that catalyzes the reaction leading to the formation of this compound.
Allantoin and uricase
66
58. Serotonin is formed by the hydroxylation of (......)
by tryptophan hydroxylase and the removal of the (......)
group.
tryptophan
carboxyl
67
59. Besides ammonium ion and carbon dioxide, what compound
is uracil degraded into?
Beta-alanine
68
60. The α-amino group of most amino acids is transferred to (......) by the action of glutamate transaminase,
with (......) as a coenzyme
alpha-ketoglutarate
pyridoxal phosphate
69
61. Name the allosteric activators of glutamate dehydrogenase.
ADP - activates, (GTP - inhibits)
70
62. List, in order, the intermediates in the serine synthesis
pathway, starting from the precursor compound:
3-phosphoglycerate, 3-phosphopyruvate and 3-phosphoserine.
71
63. Provide the name of the cofactor that is essential for the
activity of carbamoyl phosphate synthetase I.
N-acetylglutamate (as well as Mg2+ and ATP)
