Nucleotides

Question 1

What phase of mitosis do DNA and histone synthesis occur?

Answer 1

S phase

Question 2

Condensed chromatin, darker on EM, transcriptionally inactive, sterically inaccessible

Answer 2

Heterochromatin

Question 3

Less condensed chromatin, lighter on EM, transcriptionally active, sterically accessible

Answer 3

Euchromatin

Question 4

Which has stronger bond? GC or AT

Answer 4

GC, it has 3 H bonds, compared to AT, 2 H bonds

Question 5

Amino acids necessary for purine synthesis

Answer 5

Glycine
Aspartate
Glutamine

Question 6

Drug that inhibits dihydroorotate dehydrogenase

Answer 6

Leflunomide

Question 7

3 Drugs that inhibit dihydrofolate reductase

Answer 7

Methotrexate
Trimethoprim
Pyrimethamine

Question 8

Drug that inhibits thymidylate synthase

Answer 8

5-Fluorouracil

Question 9

Drug that inhibit de novo purine synthesis

Answer 9

6-mercaptopurine (azathioprine)

Question 10

Drugs that inhibit inosine monophosphate dehydrogenase

Answer 10

Mycophenolate

Ribavirin

Question 11

Drug that inhibits ribonucleotide reductase

Answer 11

Hydroxyurea

Question 12

Defective purine salvage due to absent HGPRT

Answer 12

Lesch-Nyhan Syndrome

Question 13

What is enzyme is absent in Lesch-Nyhan syndrome?

Answer 13

HGPRT

Question 14

What does HGPRT do?

Answer 14

Converts hypoxanthine to IMP and guanine to GMP

Question 15

Symptoms of lesch-nyhan syndrome

Answer 15

Hyperuricemia
Gout
Pissed off (aggression, self-mutilation)
Retardation (intellectual disability)
Dystonia

Question 16

Treatment of lesch-nyhan syndrome

Answer 16

Allopurinol

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