Nucleotide synthesis Flashcards Preview

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Flashcards in Nucleotide synthesis Deck (11):
1

PRPP synthetase catalyzes which reaction? What are inhibitors and activators?

Takes ribose-5-phosphate and phosphorylates it to ribose-5-phosphate PRPP
Inhibited by ADP and GDP

2

What enzyme catalyzes PRPP to PRA?
What are its allosteric regulators?

Amidoribosyltransferase
Activated by PRPP
Inhibited by GMP, AMP

3

What is the enzyme that catalyzes IMP to adenylosuccinate? Regulation?

Adenylosuccinate synthase
Inhibited by AMP (end product)

4

What is the enzyme that catalyzes IMP to Xanthosine-5'-monophosphate? Regulation?

IMP dehydrogenase
Inhibited by GMP

5

Allopurinol is converted to what, which inhibits what enzyme?

Oxypurinol, inhibiting Xanthine oxidase

6

What is the enzyme that converts UTP to CTP? Where does the amino group come from?

CTP synthase.
Q

7

Carbamoyl Phosphate synthetase II is regulated how?

Inhibited by UTP
Activated by PRPP

8

What enzyme takes nucleoside 2'-diphosphates nucleotides to 2'DEoxynucleotide 5'-phosphates?

Ribonucloetide reductase

9

What chemical must be oxidized in the process of ribonucleotide reductase's activity? How is it reduced back?

Thioredoxin
NADPH

10

What is the pharmacological inhibitor of ribonucleotide reductase? What is the consequence of this drug?

Hydroxyurea.
Inhibited cell proliferation

11

What reaction does Thymidylate synthase catalyze? What is oxidized in the process?

dUMP to dTMP
N5,N10 methyl THF to dihydrofolate