Chapter 26 (Nucleotide Metabolism) Flashcards
Nucleotide biosynthesis is done by (all/some) tissues and occurs in the ___ of the cell
all
cytosol
First committed step to nucleotide biosynthesis
CPS II
Know pathway for CTP synthesis
Do it
Whenever we use Gln as a nitrogen source we need the enzyme ___
GAT
First committed step to purine nucleotide biosynthesis
Glutamine phosphoribosyl amidotransferase
AIR Carboxylase
known as the ancestral protein from which all biotin enzymes evolved
IMP to GMP is ___ dependent
ATP
IMP to AMP is ___ dependent
GTP
When ATP/GTP is high, IMP is moved toward ___ biosynthesis
GMP
When ATP/GTP is low, IMP is moved toward ___ biosynthesis
AMP
Gravely urine is caused by a deficiency of the enzyme ___
APRT (found in AMP biosynthesis)
Lesch-Nyhan Syndrome is caused by a deficiency of the enzyme ___
HGPRT
causes in increase in [PRPP] which leads to an increase in [purine rings]
causes self mutilation
Deoxyribonucleotides have one function:
storing genetic information in DNA
Class (#) is the most common class of Ribonucleotide Reductases and generates a ___ radical
I
tyrosine
When ATP binds to the active site of Ribonucleotide Reductase the enzyme turns (on/off)
on
When dATP binds to the active site of Ribonucleotide Reductase the enzyme turns (on/off)
off
Order of transformation when ATP binds to active site of Ribonucleotide Reductase
ATP dATP dGMP dAMP dATP
Binding: Products: CDP: UDP: GDP: ADP:
dCTP
dTTP
dGTP
dATP
Fluorouracil
used in chemotherapy as a trojan horse inhibitor
Stops production of all dTTP
- inhibits immune/hair proliferation
PRPP is inhibited by high concentrations of:
IMP
AMP
GMP
