P3 BIOCHEMISTRY Flashcards
Nucleotides are composed of
- nitrogenous base
- pentose monosaccharide
- phosphate groups
nitrogenous bases families
purines , pyrimidines
major site of synthesis of purine
liver
sites that cannot produce purine
RBC , polymorphonuclear WBC , brain
purine synthesis pathways
- de novo
- salvage
in de novo pathway , nitrogen 3 & 9 are derived from
glutamine
in de novo pathway , nitrogen 1 is derived from
aspartate
how many ATPs are used in de novo pathway
6 ATP / 1 IMP
AMP , GMP precursor
IMP
enzyme that converts AMP & GMP to ATP & GTP
mono & diphosphate kinase
Committed step in de novo pathway
Addition of an amino group from glutamine to PRPP to form 5-phosphoribosyl-1-amine
source of energy in formation of AMP
GTP
source of energy in formation of GMP
ATP
regulation of AMP & GMP formation by
Phospho-ribosylpyrophosphate synthetase
Phospho-ribosylpyrophosphate
synthetase enzyme is inhibited by
TMP , AMP , GMP
ATPs used in salvage pathway
1 ATP
synthesis of purine in salvage pathway is from
Pre-existent nucleic acids
absence of HGPRT , Pts will develop what syndrome
lesch-nyhan syndrome
lip & finger biting , gout , hyperuricemia
all are few of symptoms associated with what syndrome
Lesch–Nyhan syndrome
absence of xanthine oxidase , Pts will develop
Xanthinuria
a genetic disease resulting from a defect in adenosine deaminase.
Severe combined immunodeficiency (SCID)
main exertion method for uric acid
in urine
site of synthesis for uric acid
liver
site of uric acid elimination
Kidneys
