Purine Metabolism- Lecture 10/25/21

Question 1

Purines

Answer 1

Adenine, Guanine

Question 2

Pyrimidines

Answer 2

Thymine and cytosine (uracil)

Question 3

One carbon transfer in Pyrimidine synthesis

Answer 3

N10 Formyl THF

Question 4

Inositate

Answer 4

Product of de novo synthesis

Question 5

Salvage pathway

Answer 5

Add base to PRPP

Question 6

HGPRT

Answer 6

Hypoxanthine, guanine purine ribotransferase

Question 7

Hypoxanthine

Answer 7

Base of inositate

Question 8

Gout mutation

Answer 8

Partially defective HGPRT, PRP synthetase inhibition

Question 9

Allopurinol

Answer 9

ANalogue of hypoxanthine used to treat gout

Question 10

Lesch-Nyhan syndrome

Answer 10

Lack functional HCPRT

Question 11

Uric acid

Answer 11

Excretion product of purine breakdown

Question 12

Adenosine deaminase deficiency

Answer 12

Causes severe combined immunodeficiency (SCID), no T and B cells

Question 13

Inhibitors of purine biosynthesis (2)

Answer 13

Sulfanaminides, p-aminobenzoic acid

Inhibit synthesis of folate in bacteria, preventing them from synthesizing DNAe

Question 14

Pyrimidine Atom sources

Answer 14

Carbamoyl-phosphate and aspartate

Question 15

Carbamoyl phospate synthase II cellular location

Answer 15

Cytoplasm

Question 16

Orotidylate

Answer 16

Intermediate on the way to UMP

Question 17

Ribonucleotide reductase

Answer 17

Extremely regulated, makes deoxyribonucleotides, uses FADH and NADPH

Question 18

Fluorouracil

Answer 18

Inhibits thymidine synthase, used as chemotherapeutic agent

Question 19

Methotrexate

Answer 19

Folate analogue competitive inhibitor of dihydrofolate reductase, cancer treatment