Enzymes

Question 1

dyhydroorotate DH - Rx? and Pathway?

Answer 1

Leflunomide; pyrimidine synthesis

Question 2

dihydrofolate reductase

Answer 2

MTX, TMP, Pyrimethamine; pyrimidine synthesis

Question 3

thymidylate synthase - Rx? active form? pathway?

Answer 3

5-FU, 5-FdUMP; pyrimidine synthesis

Question 4

inosine monophosphate DH

Answer 4

Mycophenalate, ribavarin; purine synthesis

Question 5

ribonucleotide reductase Rx? pathway?

Answer 5

hydroxyurea; both purine and pyrimidine synthesis

Question 6

Adenosine deaminase def - leads to what Dx? what substrate inc?

Answer 6

AR SCID, inc dATP

Question 7

HGPRT def? - Sx? Inc what? Inheritance?

Answer 7

XLR
Hyperuricemia - "orange sand in diaper", "frost on skin under diaper"
Gout
Pissed off (aggression, self mutilation)
Retardation (intellectual disability)
T- dysTonia

Inc uric acid, and de novo purine synthesis

Question 8

Tx of HGPRT?

Answer 8

Allopurinol, Febuxostat

Question 9

Another name of helicase?

Answer 9

TF II H

Question 10

DNA topoisomerases - which Rx targets prokaryotic Topoisomerase II, IV? Which Rx targets eukaryotic topoisomerase II? Eukaryotic topoisomerase I ?

Answer 10

Prokaryotic - Flouroquinolones
Eukaryotic II - Etoposide, Teniposide
Euk I - Irinotecan, topotecan

Question 11

Difference between DNA polymerase I and III in terms of their exonuclease function?

Answer 11

III - has 3’ –> 5’ exonuclease function (but 5’ –> 3’ SYNTHESIS)

I - same fxn, but ALSO has 5’ –>3’ exonuclease funtion
Remember that #1 goes both ways

Question 12

Telomerase - add what kind of repeats to 3’ end?

Answer 12

adds TTAGGG repeats – “TTAGGG the end”:

Question 13

Two parts to Telomerase?

Answer 13

TERT - rev transcriptase

TERC - RNA template - repeatedly read by TERT to add TTAGGGs

Question 14

formation of PDE bonds within a strand of dsDNA?

Answer 14

Ligase (joins Okazaki fragments)

Question 15

Topoisomerase function?

Answer 15

create single/double strand breaks in helix to add or remove super coils

Question 16

Low glucose inc activity of what enzyme, allowing for switch to lactose metabolism?

Answer 16

AC (lac operon assoc’n)

Question 17

Which enzyme defective in xeroderma pigmentosum? leads to what issue in terms of DNA repair?

Answer 17

endonucleases - leading to issue with nucleotide excision repair

Question 18

location of RNA polymerase II binding?

Answer 18

opens DNA at Promoter site.

Question 19

Function of eukaryotic RNA polymerase I, II, III?

Answer 19

rRNA, mRNA, tRNA

Question 20

(-)’n of RNA polymerase II?

Answer 20

alpha Amanitin toxin

Question 21

(-)’n of RNA polymerase in prokaryotes? (Rx)

Answer 21

Rifampin

Question 22

(-)’n of RNA polymerase in pro and eukaryotes?

Answer 22

Actinomycin D

Question 23

what enzyme adds the poly-A tail? Does it need a template to do so?

Answer 23

poly-A polymerase does not need a template

Question 24

Enzyme responsible for binding of charged tRNA to codon?

Answer 24

aminoacyl tRNA synthase