Name the factor of protein nature produced by T- or B-lymphocytes at viral infections in patients:
A. Calmodulin
B. Calcitonin
C. Parathyroid hormone
D. Interferon gamma
E. Calcitriol
Prostaglandin is a product of:
A. A type of vasoactive system
B. Cyclooxygenase system
C. Lipooxygenase system
D. Complement system
E. Hydrogen peroxide myeloperoxidase halogen system
A 32-year-old female patient consulted a doctor about the absence of lactation after parturition. Such disorder might be explained by the deficit of the following hormone:
A. Thyrocalcitonin
B. Somatotropin
C. Prolactin
D. Glucagon
E. Vasopressin
Prostaglandin synthesis is partially switched off by:
A. Cyclooxygenase inhibition
B. HMP reductase
C. Peroxidase
D. Reductase activation
E. Lipoxygenase inhibition
Which of the following compound antagonizes the actions of insulin in the liver?
A. Substance P
B. Vasoactive intestinal peptide
C. Growth hormone
D. Neuropeptide A
E. Neuropeptide Y
For glucose entry into the cells, insulin is required in all cells except that of:
A. Red Blood Cells
B. Liver
C. Heart
D. Renal medulla
E. Pancreas
Examination of a patient revealed overgrowth of facial bones and soft tissues, tongue enlargement, wide interdental spaces in the enlarged dental arch. What changes of the hormonal secretion are the most likely?
A. Hyposecretion of the somatotropic hormone
B. Hypersecretion of the somatotropic hormone
C. Hyposecretion of insulin
D. Hyposecretion of thyroxine
E. Hypersecretion of insulin
Choose the condition for stimulation of glucagon secretion by pancreas:
A. Low levels of calcium in the blood
B. High levels of calcium ions in the blood
C. Low levels of glucocorticoids in the blood
D. Low levels of glucose in the blood
E. High levels of pyruvic acid in the blood
A patient who suffers from pneumonia has high body temperature. What biologically active substances play the leading part in origin of this phenomenon?
A. Bradykinin
B. Leukotrienes
C. Histamine
D. Serotonin
E. Interleukin
Hyperpigmentation is considered at patients with Addison`s disease. Propose the hormone whose high level in the blood can cause this state:
A. Prolactin
B. FSH
C. MSH
D. TSH
E. ACTH
A middle-aged man went to a foreign country because he had been offered a job there. However he had been unemployed for quite a long time. What endocrine glands were exhausted most of all in this man?
A. Parathyroid glands
B. Seminal glands
C. Substernal gland
D. Adrenal glands
E. Thyroid gland
Acromegaly in patient is associated with excessive synthesis of a hormone:
A. Melatonin
B. Vasopressin
C. Thyrotropin
D. Oxytocin
E. Somatotropin
A man after 1,5 liter blood loss has suddenly reduced diuresis. The increased secretion of what hormone caused this diuresis alteration?
A. Natriuretic
B. Vasopressin
C. Cortisol
D. Parathormone
E. Corticotrophin
Porphyrin is formed by joining together four pyrrole rings by means of _?___bridges:
A. Hydroxy
B. Hydrogen
C. Phosphate
D. Propylene
E. Methylene
The enzymes that synthesize delta-amino levulinate (from succinyl CoA and glycine) and produce pyruvate (from cysteine) are both:
A. Pyridoxal phosphate dependent
B. Metalloproteins
C. Flavoproteins
D. NADH dependent
E. Biotin dependent
Bilirubin indexes may be absolutely identical in cases of hepatic and obstructive jaundices. Choose the test that can confirm the liver parenchyma damage:
A. Uric acid determination in blood plasma
B. Determination of ketone bodies in the urine
C. Determination of glucose in the urine
D. Determination of alanine aminotransferase activity in the blood plasma
E. Determination of the glucose concentration in the blood plasma
Heme to bilirubin conversion is carried out by
A. Heme oxygenase
B. Heme reductase
C. Heme dehydrogenase
D. Heme isomerase
E. Heme hydrolase
Porphobilinogen in urine produces pink color with:
A. Ehrlich’s aldehyde reagent
B. Biuretic reagent
C. Benedict’s reagent
D. Fouchet’s reagent
E. Sodium nitroprusside
A patient with jaundice has high bilirubin that is mainly indirect (unconjugated), high concentration of stercobilin in the stool and urine. The level of direct (conjugated) bilirubin in the blood plasma is normal. What kind of jaundice can you think about?
A. Gilbert’s disease
B. Hemolytic
C. Neonatal jaundice
D. Parenchymal (hepatic)
E. Mechanical
Patients having obstructive jaundice do not excrete this at all in urine:
A. Bilirubin
B. Urea
C. Urobilionogen
D. Urate
E. Glycocholate
Examination of initial molecular structure revealed substitution of the glutamic acid by valine. What inherited pathology is it typical for?
A. Favism
B. Hemoglobinosis
C. Thalassemia
D. Sickle-cell anemia
E. Minkowsky-Shauffard disease
Enzymatic jaundices are accompanied by abnormal activity of UDP-glucuronyltransferase. What compound is accumulated in blood serum in case of these pathologies?
A. Choleglobin
B. Conjugated bilirubin
C. Hydrobilirubin
D. Unconjugated bilirubin
E. Dehydrobilirubin
Which of the following is a precursor of protoporphyrin?
A. Proline
B. Glycine
C. Alanine
D. Histidine
E. Leucine
Bilirubin is produced from:
A. Uric acid
B. Albumin
C. Glucose
D. Haemoglobin
E. Stercobilinogen
A full-term newborn child has yellowish skin and mucous membranes. This might be probably caused by temporary deficiency of following enzyme:
A. Heme synthetase
B. Heme oxygenase
C. UDP glucoronyltransferase
D. Uridine transferase
E. Biliverdin reductase
Which of the following can be a homologous substitution for N-terminal valine (6) in beta-subunits of hemoglobin to form hemoglobin S?
A. Glutamic acid
B. Lysine
C. Phenylalanine
D. Alanine
E. Isoleucine
A mother consulted a doctor about her 5-year-old child who develops erythemas, vesicular rash and skin itch under the influence of sun. Laboratory studies revealed decreased iron concentration in the blood serum, increased uroporphyrinogen I excretion with the urine. What is the most likely inherited pathology in this child?
A. Erythropoietic porphyria
B. Hepatic porphyria
C. Methemoglobinemia
D. Intermittent porphyria
E. Coproporphyria
True regarding conversion of deoxyhemoglobin to oxyhemoglobin in lungs is:
A. Binding of oxygen causes release of phosphate
B. One mole of deoxyhemoglobin binds two moles of 2,3-DPG
C. Binding of oxygen causes release of proton
D. pH of blood has no affect on the binding of oxygen
E. Binding of oxygen causes increased binding of 2,3-DPG
Membrane fluidity is increased by increased content of:
A. Lauric acid
B. Cholesterol
C. Linoleic acid
D. Stearic acid
E. Palmitic acid
In a human genome project scientists notice, that one strand of the DNA molecule contains 20 thymine (T), 25 cytosine (C), 30 guanine (G) and 22 adenine (A) residues. How many of each of the bases is found in complete double-stranded molecule
A. T=42, C=55, G=55, A=42
B. T=22, C=30, G=25, A=20
C. T=44, C=60, G=50, A=40
D. T=40, C=50, G=60, A=44
E. T=42, C=50, G=60, A=42
According to the model of double DNA helix that was suggested by Watson and Greek, it was astablished that one of chains would not be lost during replication and the second chain would be synthesized complementary to the first one. What way of replication is it?
A. Conservative
B. Semicomservative
C. Analogous
D. Identical
E. Dispersed
Which one of the following is the complementary
sequence of 5’-TTAAGCTAC-3’?:
A. 5’CCGGATCGT3’
B. 5’GTAGCTTAA3’
C. 5’TTAAGCGTAC3’
D. 5’AATTCGCATG3’
E. 5’CATGCGAATT3’
Triple hydrogen bonds are found between which base pairs:
A. A-G
B. C-T
C. A-T
D. C-U
E. C-G
At the physiological pH the DNA molecules are:
A. Uncharged
B. Positively charged
C. Neutral
D. Negatively charged
E. Amphipathic
Choose the qualitative reaction on carbohydrate residue of nucleic acids:
A. Millon`s reaction
B. Barfed`s reaction
C. Diphenylamine test
D. Biuretic reaction
E. Molybdenic test
Choose the correct definition of the term “modified base”:
A. Purine or pyrimidine attached to deoxyribose
B. A nitrogen containing ring other than a purine or pyrimidine that is part of a nucleotide
C. A purine or pyrimidine that has been altered
D. A purin or pyrimidine attached to a sugar by O-glycoside linkage
E. Purine or pyrimidine attached to ribose
The major driving force for the formation of membrane bilayer is
A. Electrostatic attractions
B. Hydrogen bonding
C. All proposed
D. Van der Waals forces
E. Hydrophobic interactions
Nucleic acids have acid properties due to the presence of residues in their structure:
A. Ribose
B. Guanine
C. Adenosine
D. Phosphoric acid
E. Deoxyribose
Nowadays about 50 minor bases have found in the t-RNA structure besides the main four nitrogenous bases. Choose the minor nitrogenous base:
A. Adenine
B. Dihydrouracil
C. Cytosine
D. Uracil
E. Cysteine
Which of the following is responsible for increasing the fluidity of the membrane:
A. Palmitic acid
B. Stearic acid
C. Cholesterol ester
D. Cholesterol
E. Linoleic acid
Chargaff rule states that
A. A=U=T=G=C
B. A+T=G+C
C. A+G=T+C
D. A/T=G/C
E. None of the above
The basic protein, which functions in the packaging of DNA in chromosomes, is:
A. Collagen type V
B. Hyaluronic acid binding protein
C. Fibrinogen
D. Collagen type I
E. Histone
Deoxyribose is different from ribose by:
A. The presence of hydroxyl group at the second carbon atom
B. The presence of amino group
C. The presence of hydroxyl group at the third carbon atom
D. The quantity of carbon atoms
E. The absence of hydroxyl group at the second carbon atom
Biological membrane contains all the following except
A. Prostaglandins
B. Cholesterol
C. Steroid receptors
D. Cytochrome P450
E. Na<sup>+</sup>/K<sup>+</sup>-ATPase
Due to complete hydrolysis of DNA, we will get all of the following except:
A. Pyrimidine bases
B. Phosphoric acid
C. Adenosine
D. Deoxyribose
E. Purine bases
Point out the role of proteins located in the cellular membrane:
A. Glucose transport channel
B. Enzyme
C. All the positions are right
D. To be receptor for hormone
E. Ion transport channel
Which of the following membrane has the highest protein content per gram of tissue:
A. Myelin sheath
B. Outer mitochondrial membrane
C. Inner mitochondrial membrane
D. Nuclear membrane
E. Plasma membrane
Point out products of guanosine degradation in tissues formed at first reaction:
A. Guanine, phosphate
B. Guanine, pyrophosphate
C. Ribose, phosphate
D. Guanine, ribose-5-phosphate
E. Ribose, pyrophosphate
Beta-alanine is a degradation product of:
A. Guanylate
B. Thymidylate
C. Uridylate
D. Adenosine
E. Albumin
Point out the amino acid used both in AMP and UMP de novo synthesis:
A. Alanine
B. Aspartic acid
C. Glutamic acid
D. Inosinic acid
E. Glycine
Increased serum uric acid levels occur in:
A. Von Gierke`s disease
B. Leukemia
C. All proposed
D. Disturbances of PRPP synthase regulation
E. Lesh-Nyhan syndrome
A 42-year-old man suffering from gout has increased level of urinary acid in blood. Allopurinol was prescribed to decrease the level of urinary acid. Competitive inhibitor of what enzyme is allopurinol?
A. Hypoxanthine phosphoribosiltransferase
B. Adenine phosphoribosiltransferase
C. Adenosine deaminase
D. Xanthine oxidase
E. Guanine deaminase
An oncological patient was administered methotrexate. With the lapse of time the target cells of the tumour lost sensitivity to the preparation. We can observe changes in the gene expression of the following enzyme:
A. Folate oxidase
B. Folate decarboxylase
C. Dihydrofolate reductase
D. Thiaminase
E. Desaminase
A gout is developed in patients when the activity of certain enzyme of purine nucleotide de novo synthesis is higher (genetic defect of enzyme) then normal. Point out it:
A. 5’-nucleotidase
B. PRPP aminotransferase
C. Adenylsuccinate lyase
D. Adenylic acid deaminase
E. Adenylate cyclase
What enzyme deficiency will develop in a young male X-linked recessive disorder with hyperuricemia and mild retardation?
A. Homogentisate oxidase defective enzymes
B. Branch chain amino acids metabolites deficiency
C. Phenylalanine hydroxylase deficiency
D. Hypoxanthine phosphoribosyl oxidase deficiency
E. Hypoxanthine phosphoribosyltransferase deficiency
A gout is developed in patients when the activity of certain enzyme of purine nucleotide de novo synthesis is higher (genetic defect of enzyme) then normal. Point out it:
A. Adenylic acid deaminase
B. PRPP aminotransferase
C. 5’-nucleotidase
D. Adenylsuccinate lyase
E. Adenylate cyclase
The UMP degradation in human tissues is associated with formation of:
A. Uric acid
B. Aspartic acid
C. Beta-alanine
D. Beta-aminoisobutyric acid
E. Inosinic acid
A doctor administered allopurinol to a 26-year-old young man with the symptoms of gout. What pharmacological action of allopurinol ensures therapeutical effect?
A. By general analgetic effect
B. By general anti-inflammatory effect
C. By inhibiting of uric acid formation
D. By increasing of uric acid excretion
E. By inhibiting of leucocyte migration into the joint
Two carbon atoms and the nitrogen one of the imidazole fragment in purine base skeleton are got from only one amino acid in the de novo synthesis. Name it:
A. Asparagine
B. Glutamic acid
C. Folic acid
D. Glycine
E. Aspartic acid
The pyrimidine nucleotide UMP degradation end product in human organism is:
A. Beta-alanine
B. Aspartic acid
C. Inosinic acid
D. Beta-aminoisobutyric acid
E. Uric acid
Point out the vitamin that is actively used in the purine and pyrimidine nucleotide de novo syntheses:
A. Linolenic acid
B. Folic acid
C. Ascorbic acid
D. Pangamic acid
E. Pantothenic acid
Allopurinol is a drug used in the gout treatment. Point out the enzyme of purine nucleotide metabolism that is inhibited by it:
A. Phosphoribosyl pyrophosphate synthetase
B. Xanthine oxidase
C. Phosphoribosyl aminotransferase
D. 5’-nucleotidase
E. Adenosine deaminase
46-year-old patient complains of pain in joints that becomes stronger the day before the weather changes. Blood examination revealed an increased concentration of uric acid. This substance is accumulated in the blood of the patient due to intensive degradation of the following substance:
A. Uridine monophosphate
B. Uridine triphosphate
C. Cytidine monophosphate
D. Thymidine monophosphate
E. Adenosine monophosphate
Children with Lesch-Nyhan syndrome have a severe form of hyperuricemia accompanied by the formation of tophi, urate calculi in the urinary tracts, as well as serious neuro-psychiatric disorders. The cause of this disease is the reduced activity of the following enzyme:
A. Carbamoyl phosphate synthetase
B. Xanthine oxidase
C. Hypoxanthine guanine phosphoribosyl transferase
D. Thymidylate synthase
E. Dihydrofolate reductase
Call, please, special synthesis that may be considered as the way for ammonia neutralization in humans:
A. UMP synthesis
B. NAD synthesis
C. Ammonia salts formation
D. AMP synthesis
E. Protein synthesis
Point out the index, whose concentration is determined in the blood plasma of patients with gout:
A. Alpha-Alanine
B. Beta-Alanine
C. Urea
D. Beta-Aminoisobutyric acid
E. Uric acid
Terminal product of purine metabolism in non-primate mammals is:
A. Carbon dioxide and water
B. Urea
C. Ammonia
D. Uric acid
E. Allantoin
Severe combined immunodeficiency disease is associated with deficiency of :
A. Myeloperoxidase
B. Glucose-6-phosphatase
C. Adenosine deaminase
D. DNA polymerase III
E. HGPRTase
Pterin derivatives (aminopterin and methotrexate) are the inhibitors of dihydrofolate reductase so that they inhibit the regeneration of tetrahydrofolic acid from dihydrofolate. These drugs inhibit the intermolecular transfer of monocarbon groups, thus suppressing the synthesis of following polymer:
A. Homopolysaccharides
B. Glycosaminoglycans
C. DNA
D. Protein
E. Gangliosides
The pyrimidine nucleotide synthesis features are all right except:
A. Carbamoyl-phosphate synthase II is activated by PRPP
B. Phosphoribosyl pyrophosphate is used
C. All the UMP nitrogen atoms are got from ammonia molecules
D. The initial substrate (carbamoyl phosphate) may be formed from glutamine, CO<sub>2</sub> with ATP use
E. Synthesis starts with the aspartic acid
The terminal product of purine nucleotides catabolic pathways in humans is:
A. Oxaloacetate
B. Pyruvate
C. Uric acid
D. Beta-alanine
E. Beta-aminoisobutyric acid
Choose the main place for r-RNA production:
A. Nucleus
B. Nucleolus
C. Ribosome
D. Endoplasmic reticulum
E. Cytoplasm
Methotrexate (structural analogue of the folic acid which is competitive inhibitor of the dihydrofolatreductase) is prescribed for treatment of the malignant tumour. On which level does methotrexate hinder synthesis of the nucleic acids?
A. Transcription
B. Reparation
C. Mononucleotide synthesis
D. Processing
E. Replication
Which of the following step is not a part of Polymerase Chain Reaction:
A. Denature of DNA
B. Chain extension by DNA polymerase and deoxyribonucleoside
C. Use of restriction endonucleases which leave double stranded DNA
D. Primer construction
E. Use of restriction endonucleases which leave single stranded DNA
The sigma subunit of prokaryotic RNA polymerase:
A. Specifically recognizes the promoter site
B. Is part of the core enzyme
C. Is inhibited by Alpha-amanitin
D. Specifically recognizes the operator site
E. Binds the antibiotic rifampicin
RNA that contains AIDS virus penetrated into a leukocyte and by means of reverse transcriptase forced a cell to synthesize a viral DNA. This process is based upon:
A. Reverse translation
B. Operon repression
C. Operon depression
D. Convariant replication
E. Reverse transcription
Okazaki fragments are formed during the synthesis of:
A. Legging strand of DNA
B. Leading strand of DNA
C. rRNA
D. tRNA
E. mRNA
Restriction enzymes which have revolutionized the field of genetic engineering have been found in:
A. Humans
B. Viruses
C. Animals
D. Plants
E. Bacteria
One of the following mutations is potentially lethal. Point out it:
A. Insertion of one base
B. Substitution of methylcytosine for cytosine
C. Transvertion
D. Substitution of guanine for cytosine
E. Substitution of adenine for cytosine
Which of the following is not a post transcriptional modification of RNA?
A. 3’-polyadenylation
B. Splicing
C. None of the above
D. 5’-capping
E. Glycosylation
In some regions of South Africa there is a spread sickle-shaped cell anemia, in which erythrocytes have shape od a sickle as a result of substitution of glutamine by valine in the hemoglobin molecule. What is the cause of this disease?
A. Disturbance of mechanisms of genetic information realization
B. Genomic mutations
C. Crossingover
D. Gene mutation
E. Transduction
Okazaki fragment is:
A. DNA fragment with RNA head
B. RNA fragment with DNA head
C. RNA fragment
D. None
E. DNA fragment
Xeroderma pigmentosum is produced as a result of a defect in:
A. DNA ligase
B. DNA polymerase I
C. DNA polymerase II
D. DNA polymerase III
E. DNA exonuclease
DNA without introns is:
A. Nuclear DNA
B. Mitochondrial DNA
C. C DNA
D. Z DNA
E. B DNA
Replication and transcription are similar processes mechanistic terms because both:
A. Use deoxyribonucleotides as precursors
B. Use DNA polymerase III
C. Use RNA primers for initiation
D. Involve phosphodiester bond formation with elongation occurring in the 5’-3’ direction
E. Are semi conserved events
Choose the inhibitor of DNA synthesis from following list:
A. Penicillin
B. Polymyxins
C. Tetracycline
D. Actinomycin
E. Chloramphenicol
What does restriction endonuclease cleave?
A. Polypeptide
B. Double stranded DNA
C. Single stranded DNA
D. Single stranded RNA
E. Nucleoside
An experiment proved that UV-radiated cells of patients with xeroderma pigmentosum restore the native DNA structure slower than cells of healthy individuals as a result of reparation enzyme defection. What enzyme helps this process?
A. Primase
B. DNA gyrase
C. Endonuclease
D. RNA ligase
E. DNA polymerase III
Poly (A) tail of eukaryotic m-RNA is translated into:
A. Polylysine
B. Polyproline
C. Polyglycine
D. Polymethionine
E. Polyalanine
Which one of the following is the function of small nuclear ribonucleoprotein particles (SnRNP)?
A. Termination of protein synthesis
B. Replication of DNA
C. Activation of amino acids
D. Initiation of protein synthesis
E. Processing of RNA
Which of the following is an example of a reverse transcriptase?
A. DNA Polymerase
B. RNA Polymerase
C. Gyrase
D. Telomerase
E. Helicase
In mammals, DNA synthesis occurs in which part of the cell cycle:
A. S phase
B. M phase
C. G0 phase
D. G1 phase
E. G2 phase
During replication of DNA, which one of the following enzymes produces the Okazaki fragments?
A. DNA Polymerase II
B. RNA Polymerase I
C. DNA Polymerase I
D. DNA Polymerase III
E. RNA Polymerase II
It was found out that some compounds for instance fungi toxins and some antibiotics can inhibit activity of RNA-polymerase II. What process will be disturbed in eukaryotic cell in a case of inhibition of this enzyme?
A. Translation
B. Replication
C. Reparation
D. Transcription
E. Processing
Transcription is inhibited by:
A. Sulfonylamide