20. Nucleotide Degradation

Question 1

this nucleotide cannot be cleaved by human cells

Answer 1

purines

Question 2

this nucleotide can be opened and degraded to water soluble products

Answer 2

pyrimidine

Question 3

product of degradation of purines

Answer 3

uric acid

Question 4

product of degradation of pyrimidines

Answer 4

• ß-alanine

* ß-aminoisobutyrate

Question 5

precursor for acetyl coa

Answer 5

ß-alanine

Question 6

precursor of succinyl coa

Answer 6

ß-aminoisobutyrate

Question 7

donor of ribose-5-phosphate

Answer 7

PRPP

Question 8

disease associated with accumulation of uric acid

Answer 8

gout

Question 9

is a disease caused by an enzyme deficiency resulting in a decreased ability to synthesize pyrimidines. It is the only known enzyme deficiency of the de novo pyrimidine synthesis pathway.

Answer 9

orotic aciduria

Question 10

what irreversible enzymes are required in purine salvage pathway

Answer 10

• adenine phosphoribosyl transferase (APRT)

* hypoxanthine- guanine phosphoribosyltransferase (HGPRT)

Question 11

enzyme deficiency :

HGPRT

Answer 11

Lesch-Nyhan syndrome

ÎÎ PRPP and uric acid

Question 12

enzyme deficiency :

Adenosine deaminase

Answer 12

severe combined immunodeficiency

ÎÎ dATP inhibits ribonucleotide reductas

Question 13

enzyme deficiency :

glucose-6-phosphatase

Answer 13

Von Gierke’s disease (ÎÎ ribose-5-phosphate)

Question 14

enzyme deficiency :
orotidine phosphate decarboxylase or
orotate phosphoribosyl transferase

Answer 14

orotic aciduria

Question 15

enzyme deficiency :

dihydropyrimidine dehydrogenase

Answer 15

ß- hydroxy butyric aciduria

Question 16

• X-linked
• gout
• self-mutilation
• mental retardation

Answer 16

Lesch-Nyhan syndrome

Question 17

• lymphocytopenia
• death before age 2 because of overwhelming infection
• treat with BMT, gene therapy

Answer 17

severe combined immunodeficiency

Question 18

• purine overproduction

* hyperuricemia

Answer 18

Von Gierke disease

Question 19

• poor growth
• megaloblastic anemia
• orotate in the urine

Answer 19

orotic aciduria

Question 20

orotic aciduria

tx

Answer 20

uridine

Question 21

•Severe combined immunodeficiency tx

Answer 21

BMT

gene thereapy

Question 22

• combined uraciluria - thyminuria

* impaired formation of ß-alanine and ß-aminoisobutyrate

Answer 22

ß-hydroxy-butyric aciduria