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
- Which amino acid is synthesized by the Baranowski enzyme?
Serine
- What is the final product of purine degradation in Dalmatians?
Uric acid
- Identify the direct carbon donor in the synthesis of
thymidylate?
N5N10-methylenetetrahydrofolate
- Which of the amino acids is not degraded to alpha-ketoglutarate?
Tryptophan
- Xanthylate is formed during the reactions leading to the
formation of
GMP
- Choose the amino acids that are broken down to fumarate
Tyrosine and phenylalanine
- Which of the indicated amino acids is ketogenic?
Leucine and lysine
- Which of the following amino acids is used for transporting
amino groups from working muscles?
Alanine
- Propose measures to alleviate the consequences of
argininosuccinate lyase mutations
Reduce protein intake and administer arginine
- In what form are the amino groups of amino acids excreted by
uricotelic organisms?
Uric acid
- Which of the listed amino acids does not undergo
transamination?
Lysine, proline, threonine and hydroxyproline
- Which of the listed amino acids are classified as ketogenic amino acids?
Lysine and leucine.
- Into which of the listed compounds is phenylalanine degraded, among others?
Acetoacetate and fumarate
- What is the name of the enzyme involved in the removal of
α-amino groups from serine?
Serine dehydratase
- What is the name of the enzyme that catalyzes the conversion
of biliverdin to bilirubin?
Biliverdin reductase
- Which of the listed amino acids are involved in the synthesis
of the pyrimidine ring?
Glutamine and asparagine
- Amino acids in the synthesis of the purine ring?
Glycine, asparagine and glutamine.
- Which of the listed compounds is an allosteric activator of
carbamoyl phosphate synthetase II (CPS II)?
PRPP (5-phosphoribosyl-1 pyrophosphate)
{inhibited by CTP}
- What is the molecule that allows the conversion of PRPP to IMP in the salvage pathway?
Hypoxanthine
- Which of the listed compounds serves as a transport form of
nitrogen from muscles to the liver?
Glutamine and alanine
- 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
- 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
- Besides ammonium ion and carbon dioxide, what compound is thymine degraded into?
Beta-aminoisobutyric acid
- Porphyrins are heterocyclic compounds consisting of four
(……) rings connected by (……) bridges
pyrrole
methylene
- 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
- Provide the names of the compounds from which the
synthesis of cysteine begins.
Homocysteine and serine
- Provide the names of all the active one-carbon groups carried by tetrahydrofolate
Methyl, methylene, methenyl, formyl and formimino
- What compound is the primary source of ammonia/ammonium ions that enter the urea cycle?
- Glutamine
- AMP degradation begins with the removal of the (……)
group, leading to the formation of (……).
amino
IMP
- In what form are the amino groups of amino acids excreted by ureotelic organisms?
Urea
- Which of the listed amino acids is exclusively formed by the
action of specific aminotransferases?
Aspartic acid/asparagine
(AST) and alanine (ALT) (aminotransferase abbreviations)
- Provide the names of the products of the major pathway of
glycine degradation in mammals
Carbon dioxide, ammonia and methylenetetrahydrofolate (N5,N10-methyleno-THF)
- Into which of the listed compounds is valine degraded?
Succinyl-CoA
- What is the name of the enzymatic system that catalyzes the
degradation of heme to biliverdin?
Heme oxygenase
- Provide the name of one of the heme proteins responsible for
electron transport in the respiratory chain
Cytochrome C
- What nucleotide is formed in the salvage pathway when
hypoxanthine is attached to PRPP?
Inosine monophosphate
(IMP).
- 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
- Serotonin is formed by the hydroxylation of (……)
by tryptophan hydroxylase and the removal of the (……)
group.
tryptophan
carboxyl
- Besides ammonium ion and carbon dioxide, what compound
is uracil degraded into?
Beta-alanine
- 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
- Name the allosteric activators of glutamate dehydrogenase.
ADP - activates, (GTP - inhibits)
- List, in order, the intermediates in the serine synthesis
pathway, starting from the precursor compound:
3-phosphoglycerate, 3-phosphopyruvate and 3-phosphoserine.
- 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)
