Quiz 10 - 12th of june

Question 1

Pyrimidine

Answer 1

Question 2

Purine

Answer 2

Question 3

Adenine

Answer 3

Question 4

Guanine

Answer 4

Question 5

Cytosine

Answer 5

Question 6

Uracil

Answer 6

Question 7

Thymine

Answer 7

Question 8

Orotic acid

Answer 8

Question 9

PRPP

Answer 9

Question 10

β-alanine

Answer 10

Question 11

How are nucleotides created?

Answer 11

• Majority is made in the novo synthesis
• Remaining are created by reusing nitrogen bases, through a so-called salvage synthesis

Question 12

What enzyme catalyzes this reaction?

Answer 12

Glutamine: PRPP aminotransferase

Question 13

Enzymes involved in the biosynthesis of AMP and GMP

Answer 13

1. Adenylosuccinate synthase
2. Adenylosuccinate lyase
3. IMP dehydrogenase
4. XMP-glutamine amidotransferase

Question 14

Adenylsuccinyl synthase is inhibited by..

Answer 14

• AMP

Question 14

Glutamine: PRPP amidotransferase is regulated allosterically by…

Answer 14

1. IMP, AMP and GMP - negative allosteric inhibitors
2. PRPP - positive allosteric inhibitor

Question 15

IMP dehydrogenase is inhibited by..

Answer 15

• GMP

Question 16

The GMP synthesis pathway requires… and the AMP synthesis pathway requires…

Answer 16

The GMP synthesis pathway requires… ATP

and the AMP synthesis pathway requires… GTP

Question 17

Adenine phosphoribosyltransferase catalyzes…

Answer 17

Adenine + PRPP → adenylate + PPi

Question 18

Hypoxanthine-guanine phosphoribosyltransferase
(HGPRT) catalyzes…

Answer 18

Guanine + PRPP → guanylate + PPi

Hypoxanthine + PRPP → inosinate + PPi

Question 19

Which enzyme is used here?

Answer 19

CPS 2 (carbamoyl phosphate synthetase 2)

Question 20

Which enzyme catalyzes these reactions?

Answer 20

• Aspartate transcarbamoylase

Question 21

Which enzyme catalyzes this reaction?

Answer 21

Orotidylate decarboxylase

Question 22

Which enzymes catalyze this reaction?

Answer 22

• pyrimidine monophosphate kinase
• pyrimidine diphosphate kinase