Nucleotides

Question 1

organic molecules consisting of nucleoside and a phosphate

Answer 1

nucleotides

Question 2

these are made of nitrogenous base, and a five carbon carbohydrates

Answer 2

nucleosides

Question 3

nucleotides and nucleotides serve as ____ units of the nucleic acid polymers DNA and RNA

Answer 3

monomeric

Question 4

nucleotides are obtained in the

Answer 4

diet

Question 5

nucleotides are synthesized from common nutrient by the

Answer 5

liver

Question 6

the linkage between sugar and base

Answer 6

n-B-glycosidic bonds

Question 7

the linkage between phosphate and sugar

Answer 7

phosphoester bond

Question 8

has an absence of the hydroxyl group on the 2’ carbon

Answer 8

deoxyribose

Question 9

an organic compound containing 4 N atoms, 2 carbon rings, and is made of a pyrimidine ring fused to an imidazole ring

Answer 9

purine

Question 10

an organic compound containing 2 nitrogen atoms and only contains 1 carbon ring

Answer 10

pyrimidine

Question 11

function of purines and pyrimidines

Answer 11

serves as a form of energy for cells, essential for production of DNA and RNA, proteins, starch, regulations of enzymes, and cell signaling

Question 12

requirements for purine de novo synthesis

Answer 12

glutamine, glycine, aspartate, tetrahydrofolate (vit b9), ATP, CO2

Question 13

this a pathway in which biological products is produced from intermediates in the degradative pathway of its own or a similar substance

Answer 13

salvage pathway

Question 14

a specific salvage pathway where nucleotides are synthesized from intermediates in their degradative pathway

Answer 14

nucleotide salvage pathway

Question 15

nucleotide salvage pathways are used to recover bases and nucleosides that are formed during degradation of

Answer 15

DNA and RNA

Question 16

why is nucleotide salvage pathways important?

Answer 16

in some organs, some tissues cannot undergo de novo synthesis, the salvage products can then be converted back into nucleotides

Question 17

the end product of purine catabolism in humans is

Answer 17

uric acid

Question 18

uric acid is primarily formed in the ____ and excreted by the _____ into the urine

Answer 18

liver; kidney

Question 19

an elevation of uric acid level in blood

Answer 19

hyperuricemia

Question 20

serum uric acid concentration exceeding 7 mg/dl in males and 6 mg/dl in females

Answer 20

hyperuricemia

Question 21

condition where increased excretion of uric acid in urine

Answer 21

uricosuria

Question 22

due to the accumulation of urate crystals in the synovial fluid resulting in inflammation leading to acute arthritis

Answer 22

gout

Question 23

this is when uric acid is deposited in cooler areas of the body that cause _____ , seen in the distal joints of the foot

Answer 23

tophi

Question 24

increased excretion of uric acid may cause deposition of uric acid crystals in the urinary tract leading to

Answer 24

calculi or stone formation

Question 25

about 10% of cases of primary gout are

Answer 25

idiopathic

Question 26

causes of primry gout

Answer 26

glutamine PRPP amidotransferase, active PRPP synthase, deficiency of enzymes of salvage pathway, glucose-6-phoshatase deficiency

Question 27

increased production of uric acid may be due to the enhanced turnover rate of nucleic acid as seen in rapidly growing malignant tissues, increased tissue breakdown after treatment, increased tissue damage due to trauma and raised rate of catabolism as in starvation

Answer 27

secondary hyperuricemia

Question 28

reduced excretion rate in secondary hyperuricemia as seen in

Answer 28

renal failure, treatment with thiazide diuretics lactic acidosis and keto-acidosis

Question 29

____ leads to accumulation of lactic acid

Answer 29

alcohol

Question 30

an x-linked inherited disorder of purine metabolism, characterized by HGRPTase deficiency, rate of salvage pathway is decreased resulting in accumulation of PRPP

Answer 30

lesch-nyha syndrome

Question 31

requirements for pyrimidine de novo synthesis

Answer 31

glutamine, aspartate tetrahydrofolate (vit b9), ATP, CO2

Question 32

pyrimidines are ultimately catabolized to CO2, H2O, and urea, this mainly occurs in the

Answer 32

liver

Question 33

this pyrimidine deficiency results from the absence of OPRTase and OMP decarobxylase

Answer 33

orotic aciduria

Question 34

this is characterized by excessive excretion of orotic acid in urine because of the inability to convert orotic acid to UMP causing megaloblastic anemia, and may be associated with mental and physical developmental delays

Answer 34

orotic aciduria

Question 35

treatment of orotic aciduria is done through administration of

Answer 35

UMP or uridine triacetate