Molecular Flashcards
(53 cards)
2 a.a. that histones are rich in
Lysine & arginine
neg charged DNA that loops around positively charged histone octamer consisting of [H2A, H2B, H3, H4] x 2
nucleosome
what histone binds to the nucleosome and to linker DNA to stabilize chromatin fiber
H1
3 necessary a.a. for purine synthesis
glycine, aspartate, glutamine
enzyme that converts ribonucleotides to deoxyribonucleotides in pyrimidine synthesis
ribonucleotide reductase
carbamoyl phosphate is involved in which 2 metabolic pathways…
de novo pyrimidine synthesis
urea cycle
drug that inhibits dihydroorotate dehydrogenase causing a build up of carbamoyl phosphate and low orotic acid (pyrimidine synth)
Leflunomide
2 drugs that inhibit IMP dehydrogenase in purine synthesis
Mycophenolate
Ribavirin
drug that inhibits ribonucleotide reductase
hydroxyurea
2 drugs that inhibit de novo purine synthesis
6-mercaptopurine & it’s pro drug azathioprine
drug that inhibits thymidylate synthase thereby decreasing dTMP
5-fluorouracil
3 drugs that inhibit dihydrofolate reductase (decr dTMP) in humans, bacteria, protozoa
humans- methotrexate
bacteria- TMP
protozoa- pyrimethamine
auto recessive deficiency of adenosine deaminase: excess ATP & dATP causes feedback inhib of ribonucleotide reductase - prevents DNA synth - lowers lymphocyte count
SCID
defective purine salvage d/t absent HGPRT which converts hypoxanthine to IMP and guanine to GMP to recycle purines - results in excess uric acid & de novo purine synth
X linked recessive
causes intellect disability, self mutilation, aggression, hyperuricemia, gout, dystonia
Lesch Nyhan syndrome
AUG
methionine start codon in eukaryotes
codes for N-formylmethionine in prokaryotes - stimulates neutrophil chemotaxis
UGG
tryptophan
drug that inhibits prokaryotic enzyme topoisomerase II & IV
fluoroquinolones
prokaryotic DNApol with 5’ to 3’ synth and 3’ to 5’ exonuclease proofreading
DNA polymerase III
prokaryotic DNApol that degrades RNA primer & replaces it with DNA
same functions as DNApol III but also excises RNA primer with 5’ to 3’ exonuclease
DNA polymerase I
catalyzes formation of phosphodiester bond within a strand of dsDNA (joints Okazaki fragments)
DNA ligase
RNA-dependent DNA pol that adds DNA to 3’ ends of chrom to avoid loss of genetic material with every duplication (euk only)
telomerase
DNA mutation with nt substitution causing changed a.a.
missense point mutation
DNA mutation with nt substitution causing early stop codon
nonsense point mutation
low glucose - incr adenylyl cyclase activity - incr generation of cAMP from ATP - activates catabolite activator protein - transcription increases
MOA for lac operon in E. coli with glucose absent to do lactose metabolism
