Porphyrin is formed by joining together four pyrrole rings by means of _?___bridges:

A. Hydroxy

B. Propylene

C. Phosphate

*D. Methylene

E. Hydrogen

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. Mechanical

*B. Hemolytic

C. Gilbert’s disease

D. Neonatal jaundice

E. Parenchymal (hepatic)

Bilirubin is produced from:

A. Stercobilinogen

*B. Haemoglobin

C. Glucose

D. Albumin

E. Uric acid

Which of the following can be a homologous substitution for N-terminal valine (6) in beta-subunits of hemoglobin to form hemoglobin S?

A. Isoleucine

B. Lysine

C. Phenylalanine

D. Alanine

*E. Glutamic acid

A full-term newborn child has yellowish skin and mucous membranes. This might be probably caused by temporary deficiency of following enzyme:

A. Uridine transferase

B. Heme synthetase

C. Heme oxygenase

*D. UDP glucoronyltransferase

E. Biliverdin reductase

Which of the following is a precursor of protoporphyrin?

*A. Glycine

B. Histidine

C. Alanine

D. Leucine

E. Proline

Name the hemoglobin derivative whose content is increased under carbon monoxide poisoning:

A. Para-amino benzoic acid

B. Carbhemoglobin

C. Bilirubin IX

*D. Carboxyhemoglobin

E. 1,25-dihydroxy cholecalciferol

Unloading of oxygen to tissue cells by oxy- Hb is assisted by:

A. Bohr-affect

B. 2-3 diphosphoglycerate

C. None of the proposed

*D. All proposed

E. Low PO₂ and high PCO₂ in tissues

A denaturation of proteins can be found in some substances. Specify the substance that is used for the incomplete denaturation of hemoglobin:

*A. Urea

B. Toluene

C. Nitric acid

D. Sulfuric acid

E. Sodium hydroxide

A patient presents with icteritiousness of skin, sclera and mucous membranes. Blood plasma total bilirubin content is increased, stercobilin is increased in feces, urobilin is increased in the urine of this patient. What type of jaundice is this one:

A. Obturational

*B. Hemolytic

C. Cholestatic

D. Parenchymatous

E. Gilbert`s disease

Patients having obstructive jaundice do not excrete this at all in urine:

*A. Urobilinogen

B. Urea

C. Bilirubin

D. Urate

E. Glycocholate

Heme synthesis is regulated by feedback mechanism. Choose the 5-aminolevulinate synthetase allosteric inhibitor:

A. Porphobilinogen

B. Protoporphyrin IX

C. Coproporphyrin

D. Vitamin C

*E. Heme

Jaundice treatment involves administration of barbiturates inducing the synthesis of UDP-glucuronyl transferase. Effects of barbiturates cause the production of :

A. Indirect (unconjugated) bilirubin

B. Heme

C. Protoporphyrin

D. Biliverdin

*E. Direct (conjugated) bilirubin

Examination of initial molecular structure revealed substitution of the glutamic acid by valine. What inherited pathology is it typical for?

A. Minkowsky-Shauffard disease

B. Favism

C. Hemoglobinosis

*D. Sickle-cell anemia

E. Thalassemia

Porphobilinogen in urine produces pink color with:

A. Biuretic reagent

B. Fouchet’s reagent

*C. Ehrlich’s aldehyde reagent

D. Benedict’s reagent

E. Sodium nitroprusside

Bilirubin glucuronide in the urine in the absence of urobilinogen suggests:

A. Hepatocellular jaundice

B. Congenital erythropoetic porphyria

C. Porphyria cutanea tarda

D. Hemolytic jaundice

*E. Obstructive jaundice

Enzymatic jaundices are accompanied by abnormal activity of UDP-glucuronyltransferase. What compound is accumulated in blood serum in case of these pathologies?

A. Dehydrobilirubin

B. Conjugated bilirubin

*C. Unconjugated bilirubin

D. Hydrobilirubin

E. Choleglobin

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. Methemoglobinemia

B. Coproporphyria

C. Intermittent porphyria

D. Hepatic porphyria

*E. Erythropoietic porphyria

Name blood plasma index whose content is increased mainly under condition of hemolytic anemia in patient:

A. Free amino acids

B. Uric acid

*C. Unconjugated bilirubin

D. Conjugated bilirubin

E. Urea

The enzymes that synthesize delta-amino levulinate (from succinyl CoA and glycine) and produce pyruvate (from cysteine) are both:

A. Flavoproteins

B. NADH dependent

C. Metalloproteins

*D. Pyridoxal phosphate dependent

E. Biotin dependent

A 48 y.o. patient was admitted to the hospital with complaints about weakness, irritability, sleep disturbance. Objectively: skin and scleras are yellow. In blood: conjugated bilirubin, cholamia. Feces are acholic. Urine is of dark colour (bilirubin). What jaundice is it?

A. Crigler-Najjar syndrome

B. Hemolytic

C. Parenchymatous

D. Gilbert’s syndrome

*E. Mechanic (obstractive)

What color compound may be produced across hemoglobin degradation in the spleen of humans:

A. Urea

B. Uric acid

*C. Biliverdin

D. UDP-glucuronic acid

E. Stercobilinogen

Heme to bilirubin conversion is carried out by

A. Heme dehydrogenase

B. Heme reductase

*C. Heme oxygenase

D. Heme hydrolase

E. Heme isomerase

True regarding conversion of deoxyhemoglobin to oxyhemoglobin in lungs is:

*A. Binding of oxygen causes release of proton

B. One mole of deoxyhemoglobin binds two moles of 2,3-DPG

C. Binding of oxygen causes release of phosphate

D. Binding of oxygen causes increased binding of 2,3-DPG

E. pH of blood has no affect on the binding of oxygen

A patient who suffers from congenital erythropoietic porphyria has skin photosensitivity. The accumulation of what compound in the skin cells can cause it?

A. Uroporphyrinogen II

B. Protoporphyrin

C. Coproporphyrinogen III

D. Heme

*E. Uroporphyrinogen I

Patients having obstructive jaundice do not excrete this at all in urine:

A. Urate

B. Bilirubin

C. Glycocholate

*D. Urobilionogen

E. Urea

Bilirubin is produced from:

A. Albumin

*B. Haemoglobin

C. Uric acid

D. Glucose

E. Stercobilinogen

Which of the following is seen in obstructive jaundice?

A. Excess of bile salts in feces

B. Excess of bile salts in the urine

*C. Excess of conjugated serum bilirubin

D. Excess of stercobilinogen in urine

E. Excess of urobilinogen in urine

Bilirubin indexes may be absolutely identical in cases of hepatic and obstructive jaundices. Choose the test that can confirm the liver parenchyma damage:

A. Determination of glucose in the urine

*B. Determination of alanine aminotransferase activity in the blood plasma

C. Uric acid determination in blood plasma

D. Determination of ketone bodies in the urine

E. Determination of the glucose concentration in the blood plasma

Hemoglobin catabolism results in release of iron which is transported to the bone marrow by a certain transfer protein and used again for the synthesis of hemoglobin. Specify this transfer protein:

A. Haptoglobin

B. Transcobalamin

C. Ceruloplasmin

*D. Transferrin (siderophilin)

E. Albumin

Carbon monoxide in the body is synthesized during

*A. Breakdown of hemoglobin

B. Ribosomal protein synthesis

C. Synthesis of carnitine

D. Gluconeogenesis

E. Anaerobic glycolysis

A 48-year-old patient was admitted to the hospital with complaints about weakness, irritability, sleep disturbance. Objectively: skin and scleras are of yellow colour. In blood: increased concentration of total bilirubin with prevailing direct bilirubin. The feces are acholic. The urine is dark (contains bile pigments). What type of jaundice is it?

A. Gilbert’s syndrome

B. Crigler-Najjar syndrome

*C. Mechanic

D. Parenchmatous

E. Haemolytic

Blood analysis of a patient with jaundice reveals hyperbilirubinemia, increased concentration of bile acids in the blood plasma. There is no stercobolinogen in urine. What type of jaundice is it?

A. Parenchymatous jaundice

*B. Obstructive jaundice

C. Cythemolytic jaundice

D. Hemolytic jaundice

E. Hepatocellular jaundice

A patient is ill with diabetes mellitus that is accompanied with hyperglycemia of over 7,2 millimole/L on an empty stomach. The level of what blood plasma protein can estimate the hyperglycemia rate retrospectively {4-8 weeks before examination}?

A. C-reactive protein

B. Albumin

C. Fibrinogen

*D. Glycosylated haemoglobin

E. Ceruloplasmin

Which one of the following is the complementary

sequence of 5Т-TTAAGCTAC-3Т?:

A. 5ТCCGGATCGT3Т

*B. 5ТGTAGCTTAA3Т

C. 5ТAATTCGCATG3Т

D. 5ТCATGCGAATT3Т

E. 5ТTTAAGCGTAC3Т

Point out products of guanosine degradation in tissues formed at first reaction:

A. Guanine, pyrophosphate

*B. Guanine, ribose-5-phosphate

C. Guanine, phosphate

D. Ribose, phosphate

E. Ribose, pyrophosphate

Biological membrane contains all the following except

A. Cholesterol

B. Na⁺/K⁺-ATPase

*C. Steroid receptors

D. Prostaglandins

E. Cytochrome P450

Deoxyribose is different from ribose by:

*A. The absence of hydroxyl group at the second carbon atom

B. The presence of hydroxyl group at the second carbon atom

C. The presence of amino group

D. The presence of hydroxyl group at the third carbon atom

E. The quantity of carbon atoms

Membrane fluidity is increased by increased content of:

A. Stearic acid

B. Cholesterol

*C. Linoleic acid

D. Lauric acid

E. Palmitic acid

Triple hydrogen bonds are found between which base pairs:

A. A-T

B. C-T

C. A-G

*D. C-G

E. C-U

Which of the following is responsible for increasing the fluidity of the membrane:

A. Cholesterol

B. Palmitic acid

*C. Linoleic acid

D. Cholesterol ester

E. Stearic acid

The basic protein, which functions in the packaging of DNA in chromosomes, is:

A. Fibrinogen

*B. Histone

C. Collagen type I

D. Collagen type V

E. Hyaluronic acid binding protein

Choose the qualitative reaction on carbohydrate residue of nucleic acids:

*A. Diphenylamine test

B. Biuretic reaction

C. Millon`s reaction

D. Barfed`s reaction

E. Molybdenic test

Nucleic acids have acid properties due to the presence of residues in their structure:

A. Ribose

B. Adenosine

C. Guanine

D. Deoxyribose

*E. Phosphoric acid

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. Analogous

C. Dispersed

*D. Semicomservative

E. Identical

Point out the role of proteins located in the cellular membrane:

A. Glucose transport channel

B. Enzyme

*C. All the positions are right

D. Ion transport channel

E. To be receptor for hormone

Choose the correct definition of the term Уmodified baseФ:

A. A purin or pyrimidine attached to a sugar by O-glycoside linkage

B. A nitrogen containing ring other than a purine or pyrimidine that is part of a nucleotide

C. Purine or pyrimidine attached to deoxyribose

D. Purine or pyrimidine attached to ribose

*E. A purine or pyrimidine that has been altered

The major driving force for the formation of membrane bilayer is

A. Hydrogen bonding

*B. All proposed

C. Van der Waals forces

D. Hydrophobic interactions

E. Electrostatic attractions

Which of the following membrane has the highest protein content per gram of tissue:

A. Outer mitochondrial membrane

*B. Inner mitochondrial membrane

C. Nuclear membrane

D. Plasma membrane

E. Myelin sheath

Due to complete hydrolysis of DNA, we will get all of the following except:

A. Purine bases

B. Deoxyribose

C. Pyrimidine bases

*D. Adenosine

E. Phosphoric acid

Nowadays about 50 minor bases have found in the t-RNA structure besides the main four nitrogenous bases. Choose the minor nitrogenous base:

A. Cytosine

B. Cysteine

*C. Dihydrouracil

D. Uracil

E. Adenine

Chargaff rule states that

*A. A/T=G/C

B. None of the above

C. A+T=G+C

D. A=U=T=G=C

E. A+G=T+C

At the physiological pH the DNA molecules are:

*A. Negatively charged

B. Amphipathic

C. Positively charged

D. Uncharged

E. Neutral

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=44, C=60, G=50, A=40

*B. T=42, C=55, G=55, A=42

C. T=42, C=50, G=60, A=42

D. T=40, C=50, G=60, A=44

E. T=22, C=30, G=25, A=20

The pyrimidine nucleotide UMP degradation end product in human organism is:

A. Aspartic acid

*B. Beta-alanine

C. Inosinic acid

D. Beta-aminoisobutyric acid

E. Uric acid

Beta-alanine is a degradation product of:

A. Adenosine

B. Thymidylate

C. Albumin

*D. Uridylate

E. Guanylate

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. Adenylate cyclase

B. 5’-nucleotidase

C. Adenylic acid deaminase

*D. PRPP aminotransferase

E. Adenylsuccinate lyase

Point out the index, whose concentration is determined in the blood plasma of patients with gout:

*A. Uric acid

B. Alpha-Alanine

C. Urea

D. Beta-Aminoisobutyric acid

E. Beta-Alanine

Call, please, special synthesis that may be considered as the way for ammonia neutralization in humans:

A. Ammonia salts formation

B. AMP synthesis

*C. UMP synthesis

D. NAD synthesis

E. Protein synthesis

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. Folic acid

*C. Glycine

D. Aspartic acid

E. Glutamic acid

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. Xanthine oxidase

B. Guanine deaminase

C. Hypoxanthine phosphoribosiltransferase

D. Adenine phosphoribosiltransferase

E. Adenosine deaminase

Increased serum uric acid levels occur in:

A. Lesh-Nyhan syndrome

B. Von Gierke`s disease

*C. All proposed

D. Leukemia

E. Disturbances of PRPP synthase regulation

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. Adenylsuccinate lyase

B. Adenylic acid deaminase

*C. PRPP aminotransferase

D. Adenylate cyclase

E. 5’-nucleotidase

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. DNA

B. Homopolysaccharides

C. Protein

D. Gangliosides

E. Glycosaminoglycans

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. Thymidine monophosphate

B. Cytidine monophosphate

C. Uridine monophosphate

D. Uridine triphosphate

*E. Adenosine monophosphate

The pyrimidine nucleotide synthesis features are all right except:

A. The initial substrate (carbamoyl phosphate) may be formed from glutamine, CO₂ with ATP use

B. Synthesis starts with the aspartic acid

C. Carbamoyl-phosphate synthase II is activated by PRPP

*D. All the UMP nitrogen atoms are got from ammonia molecules

E. Phosphoribosyl pyrophosphate is used

What enzyme deficiency will develop in a young male X-linked recessive disorder with hyperuricemia and mild retardation?

A. Branch chain amino acids metabolites deficiency

*B. Hypoxanthine phosphoribosyltransferase deficiency

C. Phenylalanine hydroxylase deficiency

D. Homogentisate oxidase defective enzymes

E. Hypoxanthine phosphoribosyl oxidase deficiency

Severe combined immunodeficiency disease is associated with deficiency of :

A. DNA polymerase III

B. Glucose-6-phosphatase

*C. Adenosine deaminase

D. Myeloperoxidase

E. HGPRTase

Terminal product of purine metabolism in non-primate mammals is:

A. Urea

B. Carbon dioxide and water

*C. Allantoin

D. Ammonia

E. Uric acid

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. Thiaminase

B. Desaminase

C. Folate oxidase

*D. Dihydrofolate reductase

E. Folate decarboxylase

The UMP degradation in human tissues is associated with formation of:

A. Beta-aminoisobutyric acid

*B. Beta-alanine

C. Inosinic acid

D. Aspartic acid

E. Uric acid

The terminal product of purine nucleotides catabolic pathways in humans is:

A. Beta-aminoisobutyric acid

*B. Uric acid

C. Pyruvate

D. Oxaloacetate

E. Beta-alanine

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. Dihydrofolate reductase

*D. Hypoxanthine guanine phosphoribosyl transferase

E. Thymidylate synthase

Point out the amino acid used both in AMP and UMP de novo synthesis:

A. Glutamic acid

B. Inosinic acid

C. Glycine

*D. Aspartic acid

E. Alanine

Point out the vitamin that is actively used in the purine and pyrimidine nucleotide de novo syntheses:

*A. Folic acid

B. Pangamic acid

C. Pantothenic acid

D. Linolenic acid

E. Ascorbic 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 inhibiting of leucocyte migration into the joint

C. By increasing of uric acid excretion

D. By general anti-inflammatory effect

*E. By inhibiting of uric acid formation

Allopurinol is a drug used in the gout treatment. Point out the enzyme of purine nucleotide metabolism that is inhibited by it:

A. 5’-nucleotidase

B. Phosphoribosyl pyrophosphate synthetase

*C. Xanthine oxidase

D. Phosphoribosyl aminotransferase

E. Adenosine deaminase

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. Processing

B. Replication

C. Reparation

D. Translation

*E. Transcription

Which of the following is an example of a reverse transcriptase?

A. Helicase

B. RNA Polymerase

C. DNA Polymerase

D. Gyrase

*E. Telomerase

Okazaki fragment is:

*A. DNA fragment with RNA head

B. RNA fragment

C. DNA fragment

D. None

E. RNA fragment with DNA head

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. Mononucleotide synthesis

B. Replication

C. Processing

D. Transcription

E. Reparation

Poly (A) tail of eukaryotic m-RNA is translated into:

A. Polyglycine

B. Polymethionine

*C. Polylysine

D. Polyproline

E. Polyalanine

Replication and transcription are similar processes mechanistic terms because both:

A. Use DNA polymerase III

B. Are semi conserved events

*C. Involve phosphodiester bond formation with elongation occurring in the 5’-3’ direction

D. Use deoxyribonucleotides as precursors

E. Use RNA primers for initiation

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 polymerase III

C. DNA gyrase

*D. Endonuclease

E. RNA ligase

During replication of DNA, which one of the following enzymes produces the Okazaki fragments?

*A. DNA Polymerase III

B. DNA Polymerase I

C. RNA Polymerase I

D. RNA Polymerase II

E. DNA Polymerase II

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. Crossingover

C. Transduction

D. Genomic mutations

*E. Gene mutation

Xeroderma pigmentosum is produced as a result of a defect in:

A. DNA ligase

B. DNA polymerase I

*C. DNA exonuclease

D. DNA polymerase III

E. DNA polymerase II

Restriction enzymes which have revolutionized the field of genetic engineering have been found in:

A. Viruses

B. Animals

*C. Bacteria

D. Plants

E. Humans

One of the following mutations is potentially lethal. Point out it:

A. Substitution of adenine for cytosine

B. Substitution of guanine for cytosine

C. Transvertion

D. Substitution of methylcytosine for cytosine

*E. Insertion of one base

In mammals, DNA synthesis occurs in which part of the cell cycle:

A. G0 phase

*B. S phase

C. G1 phase

D. M phase

E. G2 phase

DNA without introns is:

A. Nuclear DNA

B. C DNA

C. Z DNA

D. B DNA

*E. Mitochondrial DNA

Okazaki fragments are formed during the synthesis of:

A. Leading strand of DNA

B. rRNA

*C. Legging strand of DNA

D. tRNA

E. mRNA

Which of the following is not a post transcriptional modification of RNA?

A. Splicing

B. None of the above

*C. Glycosylation

D. 3’-polyadenylation

E. 5’-capping

Excessive ultraviolet radiation is harmful to life. The damage caused to the biological systems by ultraviolet radiation is by:

A. Deamination of DNA

*B. Formation of thymidine dimmers

C. Inhibition of DNA synthesis

D. Ionization

E. DNA fragmentation

The sigma subunit of prokaryotic RNA polymerase:

A. Specifically recognizes the operator site

B. Binds the antibiotic rifampicin

*C. Specifically recognizes the promoter site

D. Is inhibited by Alpha-amanitin

E. Is part of the core enzyme

Which of the following step is not a part of Polymerase Chain Reaction:

A. Primer construction

*B. Use of restriction endonucleases which leave double stranded DNA

C. Denature of DNA

D. Use of restriction endonucleases which leave single stranded DNA

E. Chain extension by DNA polymerase and deoxyribonucleoside

RNA-polymerase B (II) is blocked due to amanitin poisoning (poison of death-cup). What process is disturbed:

*A. Synthesis of m-RNA

B. Primer synthesis

C. Synthesis of t-RNA

D. Reverse transcription

E. Maturation of m-RNA

Which one of the following is the function of small nuclear ribonucleoprotein particles (SnRNP)?

A. Termination of protein synthesis

B. Initiation of protein synthesis

*C. Processing of RNA

D. Activation of amino acids

E. Replication of DNA

Transcription is inhibited by:

*A. Amanitin

B. Puromycin

C. Chloramphenicol

D. Streptomycin

E. Sulfonylamide

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. Convariant replication

C. Operon repression

*D. Reverse transcription

E. Operon depression

Choose the main place for r-RNA production:

*A. Nucleolus

B. Endoplasmic reticulum

C. Ribosome

D. Cytoplasm

E. Nucleus

Choose the inhibitor of DNA synthesis from following list:

A. Tetracycline

B. Penicillin

*C. Actinomycin

D. Chloramphenicol

E. Polymyxins

What does restriction endonuclease cleave?

A. Nucleoside

B. Single stranded RNA

*C. Double stranded DNA

D. Polypeptide

E. Single stranded DNA

What is the average number of high energy bonds required for the synthesis of 1 peptide bond:

A. _5

B. _1

*C. _4

D. _2

E. _3

Amino acid with a single codon is:

A. Alanine

B. Phenylalanine

*C. Tryptophan

D. Threonine

E. Tyrosine

All stated below are true about the genetic code except one. Choose it:

*A. Punctuation is present

B. Universal

C. Degenerate

D. Non overlapping

E. High specific

All amino acids are translated except one. Point out it:

A. Alanine

B. Tyrosine

C. Proline

D. Threonine

*E. Hydroxyproline

Leucine zipper motif is a mediator for:

A. Membrane attack complexes

B. Cyclic GMP

C. Cyclic AMP

*D. Binding of regulatory proteins to DNA

E. Ligand membranes

You are studying functioning of a bacteria operon. The operator gene has been released from the repressor. Immediately after his the following process will start in the sell:

A. Processing

B. Translation

C. Repression

D. Replication

*E. Transcription

Point out the chemical nature of gene:

A. Glycoprotein

B. Chromoprotein

C. The fragment of Ribonucleic acid

D. Lipoprotein

*E. The fragment of Deoxyribonucleic acid

Following organelles are involved in the formation of N-glycosylated product:

A. Nucleolus

B. Smooth Endoplasmic Reticulum

C. Ribosomes

D. Peroxisomes

*E. Golgi apparatus

In the DNA molecule the coding region reads 5’-CGT- 3’. This would code in the RNA as:

A. 5’-GCA-3’

B. 5’-GCU-3’

*C. 5’-CGU-3’

D. 5’-UCG-3’

E. 5’-ACG-3’

Amber codon refers to:

A. Initiating codon

B. Codon for Alanine

C. Codon for more than one amino acid

D. Mutant codon

*E. Stop codon

CAP (Catabolite active gene protein) in Lac operon is an example of:

A. Attenuation

B. Negative regulator of transcription

*C. Positive regulator of transcription

D. Regulatory region of DNA

E. Constitutive expression

Minor base in t-RNA is:

A. Orotic acid

B. Adenine

*C. Dihydrouracil

D. Cystine

E. Methyl xanthine

Infection diseases are treated with antibiotics (streptomycin, erythromycin, chloramphenicol). They inhibit the following stage of protein synthesis:

A. Transcription

B. Processing

C. Replication

*D. Translation

E. Splicing

Choose the substance that can stimulate LAC-operon expression in E.coli:

*A. Lactose

B. Mannose

C. Fructose

D. Glucose

E. Sucrose

The degeneration of the genetic code is explained therefore:

A. Each amino acid is coded for one triplet, only

B. “Punctuation marks” are absent in the genetic code

*C. Two or more triplets may be for one amino acid

D. The Code is single for all biologic systems

E. Genetic Code is composed of various triplets

Choose a codon composition from following list:

A. 2 complementary base pairs

B. 4 complementary base pairs on RNA

C. 2 individual nucleotides

*D. 3 individual nucleotides

E. 4 individual nucleotides

Regarding сytosolic eukaryotic translation false is:

*A. N-formyl -methionyl-tRNA will be the first to come into action

B. eIF2 shifts between GDP & GTP

C. The ribozime peptidyltransferase catalyses the formation of peptide bond

D. Releasing factor releases the polypeptide chain from the P site

E. Capping helps in attachment of mRNA to 40 S Ribosome

The primary role of chaperones is to help in:

*A. Protein folding

B. Protein degradation

C. None

D. Protein denaturation

E. Protein synthesis

The two energy rich compounds utilized for protein biosynthesis are:

*A. ATP and GTP

B. GTP and UTP

C. ATP and UTP

D. ATP and CTP

E. ATP and TTP

A mutation in the codon which causes a change in the coded amino acid, is known as

A. Somatic mutation

*B. Missense mutation

C. Recombination

D. Mutagenesis

E. Chromosomal inversions

At the stage of translation in the rough endoplasmic reticulum, the ribosome moves along the mRNA. Amino acids are joined together by peptide bonds in a specific sequence, and thus polypeptide synthesis takes place. The sequence of amino acids in a polypeptide corresponds to the sequence of:

A. rRNA nucleotides

B. tRNA anticodons

C. tRNA nucleotides

D. rRNA anticodons

*E. mRNA codons