12: Nucleotide Metabolism

Question 1

Nucletide

Answer 1

the nucleoside plus the phosphate groups

Question 2

Where does the ribose in a nucleotide come from?

Answer 2

pentose phosphate pathway

Question 3

Purines have __ ring(s)

Answer 3

2

Question 4

Pyrimidines have __ ring(s)

Answer 4

1

Question 5

Where do the amines come from in a purine?

Answer 5

aspartate and glutamine

Question 6

Folate

Answer 6

Vitamin B9 contributes to purines

Question 7

PRPP

Answer 7

phosphoribosyl pyrophosphate (activated form of ribose)

Question 8

How are the salvage and de novo pathways regulated?

Answer 8

feedback inhibition

Question 9

Salvage pathway of purine synthesis

Answer 9

guanine and adenine are synthesized from hypoxanthine

Question 10

What is guanine converted to in the salvage pathway?

Answer 10

GMP

Question 11

What is adenine converted to in the salvage pathway?

Answer 11

AMP

Question 12

What is a common precursor for GMP and AMP synthesis?

Answer 12

IMP

Question 13

What is used to make ATP in the de novo pathway?

Answer 13

GTP

Question 14

What is used to make ATP in the de novo pathway?

Answer 14

ATP

Question 15

De novo purine nucleotide synthesis

Answer 15

base needs to be built first

Question 16

T/F: Purines can quickly convert from one nucleotide to another

Answer 16

T

Question 17

Pyrimidine de novo synthesis

Answer 17

build the base and then attach it to PRPP

Question 18

What does uridine monophosphate synthase do?

Answer 18

makes uridine to uracil which is added to PRPP

Question 19

DUMPS

Answer 19

deficiency of uridine monophosphate synthase

Question 20

What does uridine monophosphate synthase do?

Answer 20

performs last 2 steps of UMP formation

Question 21

What is increased in serum for animals with DUMPS?

Answer 21

orotic acid

Question 22

What enzyme is used to synthesize deoxyribonucleotides?

Answer 22

ribonucleotide reductase

Question 23

What type of reaction is the synthesis of deoxyribonucleotides?

Answer 23

redox

Question 24

What intermediate is needed for the synthesis of deoxyribonucleotides?

Answer 24

NADPH

Question 25

What must uracil be converted to for the synthesis of deoxyribonucleotides?

Answer 25

thymidine

Question 26

What enzyme produces uric acid?

Answer 26

xanthine oxidase

Question 27

What inhibits purines forming urate?

Answer 27

allopurinol

Question 28

What is uric acid from purine breakdown in non-primate mammals excreted as?

Answer 28

allantoin