Purine, Pyrimidine and Nucleotide Metabolism: Part 1 & 2

Question 1

what is the cellular location of CPS1

Answer 1

Mitochondria

Question 2

what is the cellular location of CPS2

Answer 2

Cytosol

Question 3

which pathway is CPS1 involved

Answer 3

urea cycle

Question 4

Which pathway is CPS2 involved

Answer 4

Pyrimidine synthesis

Question 5

what is the source of nitrogen in CPS1

Answer 5

Ammonia

Question 6

what is the source of nitrogen in CPS2

Answer 6

gamma-amide group of glutamine

Question 7

what are the regulators of CPS1

Answer 7

activator: N-acetyl-glutamate

Question 8

what are the regulators of CPS2

Answer 8

activator: ATP
Inhibitor: UTP

Question 9

______ is the final breakdown product of purines

Answer 9

Uric acid

Question 10

The degradation of Cytosine leads to ______

Answer 10

Malonyl-CoA

Question 11

The degradation of Uracil leads to _______

Answer 11

Acetyl-CoA.

Question 12

The degradation of thymine leads to _______

Answer 12

Succinyl-CoA

Question 13

what is the enzyme that is lacking in Severe combined immunodeficiency syndrome (SCID)

Answer 13

adenosine deaminase (ADA).

Question 14

Gout is Caused by _______

Answer 14

overproduction of purine nucleotides via the de novo pathway.As these excess purines are degraded, it leads to uric acid.

Question 15

Lesch-Nyhan syndrome (LNS) is phenotypically characterized by ______

Answer 15

self-mutilating behaviors such as lip and finger biting and/or head banging

Question 16

The symptoms of LNS usually appear between the ages of _________.

Answer 16

3 and 6 months

Question 17

Frequently the first symptom of LNS is ________

Answer 17

the presence of orange-colored crystal-like deposits (orange sand) in the diapers of affected infants

Question 18

which drugs Block the thymidate synthase/folate metabolism cycle

Answer 18

fluorouracil and methotrexate

Question 19

A ______ a base combined with a pentose sugar.

If the sugar is phosphorylated, then the molecule is called a ________

Answer 19

Nucleoside,

Nucleotide

Question 20

The key regulated step of purine de novo synthesis is at the start, when PRPP (contains the ribose sugar) and glutamine are used by ________ to add the first nitrogen to the PRPP

Answer 20

glutamine phosphoribosyl pyrophosphate amidotransferase

Question 21

The reduction reaction that converts ribose to deoxyribose is catalyzed by an enzyme called

Answer 21

ribonucleotide reductase.

Question 22

Once UDP is converted to dUDP, it can then be dephosphorylated to make dUMP, which is then converted to dTMP by _________

Answer 22

thymidylate synthase

Question 23

What is the MOA of 6-mercaptopurine

Answer 23

inhibits AMP synthesis (anti cancer)

Question 24

What is the MOA of Azidothymidine (AZT):

Answer 24

inhibits viral polymerase (anti HIV)

Question 25

What is the MOA of Cytosine arabinoside (araC):

Answer 25

targets DNA polymerase (anti leukemia)

Question 26

What is the MOA of Acyclovir (ACV)

Answer 26

targets viral DNA polymerase and reverse transcriptase (anti Herpes simplex virus)