Practical lesson 5 metabolic pathway of nucleotides. Catabolism and anabolism

1. End product of purine catabolism is…

A. urea,

B. indole;

C. uric acid;

D. indican;

E. creatinine.

2. End product of pyrimidine catabolism is…

A. urea,

B. indole;

C. uric acid;

D. indican;

E. creatinine.

3. Patient in Lesh- Nyhan syndrome has defect in enzyme of…

A. purine degradation;

B. pyrimidine catabolism;

C. purine de novo synthesis;

D. pyrimidine de novo synthesis;

E. purine salvage.

4. Allopurinol administrated in gout is analog of…

A. uric acid;

B. xanthine;

C. guanine;

D. hypoxanthine;

E. inosine.

5. The common precursor for AMP and GMP is….

A.xanthine;

B. orotic acid;

C. xanthosine monophosphate;

D. inosine monophosphate;

E. adenylosuccinate.

6. The common precursor for pyrimidine nucleotides is….

A.xanthine;

B. orotic acid;

C. xanthosine monophosphate;

D. inosine monophosphate;

E. adenylosuccinate.

7. As sources of the nitrogen and carbon atoms of the purine ring….. are used.

A. aspartate and glycine;

B. glutamine;

C. respiratory CO₂;

D. derivatives from folic acid;

E. all answers are correct.

8. Reduction of ribonucleoside diphosphate to 2’-deoxyribonucleoside diphosphate is catalyzed by…..

A. phosphoribosyl pyrophosphate synthase;

B. carbamoyl phosphate synthase I;

C. carbamoyl phosphate synthase II;

D. xanthine oxidase;

E. ribonucleotide reductase complex.

9. Common mechanism regulation of enzymes participating in biosynthesis of purine and pyrimidine nucleotides is…

A. isosteric regulation;

B. partial proteolysis;

C. dissociation of promoters;

D. feedback regulation;

E. all answers are correct.

10. Common precursor for purine biosynthesis and pyrimidine biosynthesis is…

A. orotic acid;

B. inosine monophosphate;

C. 5-phosphorybosyl 5-pyrophosphate;

D. xanthine;

E. adenylosuccinate.

Practical lesson 6 replication. Transcription. Translation

1. Which one of the following statements about DNA is incorrect.

A. as sugar 2’- deoxyribose is used;

B. as pyrimidine components thymine and cytosine are used;

C. DNA exists as a double- stranded helical molecule;

D. during a round of replication, each of the two strands of DNA is used as a template for synthesis of a new strand;

E. processing takes place after replication

2. Between the purine and pyrimidine bases in double stranded helix molecules…. are existed.

A. hydrogen bonds;

B. Van der Waals forces;

C. hydrophobic interactions;

D. glycosidic bonds;

E. all answers are correct.

5. A transcription unit is the region of DNA including…..

A. initiator and promoter regions;

B. terminator region;

C. introns;

D. exons;

E. all answers are correct.

6. Processing of m RNA includes…

A. polyadenylation tail (3’end);

B. 5’ capping;

C. methylation of 5’ terminal guanine;

D. removal of introns and splicing of exons;

E. all answers are correct.

7. Enzyme synthesizing the precursor of messenger RNAs called ….

A.RNA polymerase I;

B.RNA polymerase II;

C.RNA polymerase III;

D. small nuclear RNA;

E. nucleotidyltransferase.

8. Spliceocome is…

A. the primary transcript of DNA combines with small ribonucleoprotein particles to folded complex;

B. the primary transcript of m RNA combines with small ribonucleoprotein particles to folded complex;

C. the primary transcript of r RNA combines with small ribonucleoprotein particles to folded complex;

D. the primary transcript of t RNA combines with small ribonucleoprotein particles to folded complex;

E. not correct answer.

7. At the replication prepriming complex includes ….Chose one incorrect answer.

A. DnaA protein;

B. single- stranded DNA- binding (SSB) proteins;

C. helix-destabilizing proteins;

D. DNA helicases;

E. DNA polymerase.

8. At the replication as nucleotide building blocks …… are used.

A.5’-deoxyribonucleoside phosphates;

B. 3’-deoxyribonucleoside phosphates;

C. 5’-deoxyribonucleoside diphosphates;

D. 3-deoxyribonucleoside diphosphates;

E. 5’-deoxyribonucleoside triphosphates.

9. Which one of the following statements about procariotic RNA polymerase is incorrect.

A. It is holoenzyme;

B. four subunits (α, α, β, β’) are responsible for the 5’→3’ polymerase activity;

C. core enzyme enables RNA polymerase to recognize promoter region on the DNA;

D. ϭ- factor possesses highly specific;

E. RNA- polymerase can recognize some termination region on the DNA.

10. The base sequence of the strand of DNA used as the template for transcription has the base sequence GATCTAC. What is the base sequence of the RNA product? (All sequences are written according to standard convention, 5’→3’).

A. CTAGATG

B. GTAGATC

C. GAUCUAC

D. CUAGAUG

E. GUAGAUC