5.01_5.02 Review

5.01
Nucleotide Chemistry

Multiple Choice

Which of the following is NOT a function of ribonucleotides?

• Second messengers

• Carriers for synthesis of lipids

• Enzyme regulation

• All other choices are functions of nucleotides

Ribonucleotide Importance

Multiple Choice

Which of the following is not part of the structure of ribonucleoside?

• Nitrogenous Base

• 5-Carbon Sugar

• Phosphate Group

• Hydroxyl Group on 2'-Carbon

Nucleotides vs Nucleosides

​Phosphate
Group

5-Carbon Sugar

5-Carbon Sugar

1'

2'

3'

4'

5'

1'

2'

3'

4'

5'

Multiple Choice

Which of the following is true regarding PURINES?

• Major purines are cytosine, uracil, thymine

• Rings made of

  9 members:

  5N + 4C

• Attaches to the ribosyl group at N1

• Pyrimidine group: Counter-clockwise numbering

  Imidazole group:

  Clockwise numbering

Multiple Choice

Common name for 2,4-dioxy-5-methyl pyrimidine:

• Orotate

• Cytosine

• Uracil

• Thymine

Multiple Choice

Type of bond between two CONSECUTIVE nucleotides:

• Hydrogen Bond

• Phosphodiester Bond

• Peptide Bond

• Glycosidic Bond

Phosphodiester Bond

5.02
Metabolism of
Purines and Pyrimidines

PURINES

2nd Division Summary

Regulation

Formation of Deoxypurines

Multiple Choice

What molecule is produced in the 1st division of de novo purine synthesis?

• Ribose

  5-phosphate

• 5-Phosphoribosyl

  1-pyrophosphate

• Inosine Monophosphate

• Xanthine Monophosphate

Multiple Choice

Which of the following is the final product of the 2nd division and what is its rate limiting enzyme?

• Inosine Monophosphate;

  Glutamine-PRPP

  Amidotransferase

• Inosine Monophosphate;

  PRA Synthase

• Hypoxanthine;

  Glutamine-PRPP

  Amidotransferase

• Hypoxanthine;

  PRA Synthase

Multiple Choice

The nitrogen members in a purine ring are contributed by these amino acids EXCEPT:

• Glycine

• Glutamine

• Aspartate

• Arginine

Multiple Choice

The carbon members in a purine ring are contributed by these molecules EXCEPT:

• Glycine

• CO2

• N10-Formyl-

  Tetrahydrofolate

• Succinyl

Multiple Choice

In the de novo pathway for purine synthesis, how many ATPs are needed to produce 1 molecule of IMP?

• 2

• 4

• 6

• 8

Multiple Select

These enzymes are essential in the formation of guanylate from guanosine:

• Guanosine Kinase

• Hypoxanthine-Guanine Phosphoribosyl

  Transferase

• Purine Nucleoside Phosphorylase

• GMP Reductase

Multiple Choice

A 5-year old boy was brought to the lab presenting gouty arthritis, poor muscle control, and wounds on the lips. Test results revealed high levels of guanine and uric acid. The child was diagnosed to have an X-linked disease. What could be an enzyme deficient in the patient?

• HGPRT

• GMP Synthetase

• GPAT

• Xanthine Oxidase

How I memorize

PYRIMIDINES

Regulation

Multiple Choice

Which of the following is the rate limiting step in pyrimidine synthesis?

• Carbamoyl Phosphate Synthetase I

• Carbamoyl Phosphate Synthase II

• Aspartate Transcarbomylase

• Dihydroorotase

Multiple Choice

Which of the following is the correct order of nucleotide synthesis in the pyrimidine de novo pathway?

• OMP → UTP → CTP → TTP

• OMP → CTP → UTP → TTP

• OMP → UTP → TTP → CTP

• OMP → TTP → UTP → CTP

Multiple Choice

This enzyme is used to produce TMP from thymine:

• Thymine Phosphoribosyl Transferase

• Thymine Phosphorylase

• Orotidine Phosphoribosyl Transferase

• None of the choices

Multiple Choice

A patient was found to have elevated orotic acid levels in their urine. Uridine was administered as treatment. Which enzyme is targeted for inhibition with this treatment?

• Orotate Decarboxylase

• CPS II

• Uridine Kinase

• OPRT

Thank you! :3