Biochemistry Info Flashcards
What AA do you need to make Purines?
Glycine
Aspartate
Glutamine
Difference between Nucleotide and Nucleoside?
Side = base + (deoxy)ribose (SUGAR)
Tide = base + (deoxy)ribose + PhophaTe
linked by 3’-5’ Phosphodiester bone
What are the 2 processes that Carbamoyl Phosphate is involved in?
1) De Novo Pyrimidine Synthesis - Glutamine to carbamoyl phosph to orotic acid
2) Urea Cycle
What does Leflunomide do?
inhibits dihydrooorotate dehydrogenase from taking Carbamoyl phosphate + Asparatate to Orotic Acid in de novo Pyr synth
What does Mycophenolate and Ribavirin inhibit?
IMP dehydrogenase making IMP to GMP
What does Hydroxyurea inhibit?
RIBONUCLEOTIDE REDUCTASE
What does 6MP and Azathioprine inhibit?
de novo Purine Synthesis from PRPP
What does 5FU inhibit?
Thymidylate Synthase - decreased dTMP
What is Lesch-Nyan Syndrome?
defective purine salvage bc absent HGPRT which converts Hypoxanthine to IMP and Guanine to GMP
Increased Uric Acid production and de novo purine synthesis - XLRecessive
Hyperuricemia
Gout
Pissed off - self mutilation and aggression
Retardation
dysTonia
Tx allopurinol and Feboxostat
What are the AA encoded by only 1 codon?
AUG - Methionine
UGG - Tryptophan
How do Floroquinolones work in DNA replication?
Antibiotics that inhibit prokaryotic enzyme topoisomerases 2 (DNA gyrase) and Topoisom IV which normally create single and double strand breaks in DNA to add or remove supercoils
What is DNA polymerase 3 and significance of it?
PROKARYOTIC ONLY
elongates leadding by adding to 3’ end
elongates laggin until reaches preceeding fragment
5’–> 3’ Synthesis
Proofreads 3’–> 5’ exonuclease
vs DNA pol 1
What is DNA pol 1 and significance?
PROKARYOTIC ONLY
Degrades RNA primer and replaces it w/ DNA
same as Pol 3 except also has 5’–> 3’ Exonuclease
What is telomerase?
RNA dependent DNA polymerase that adds DNA to 3’ ends of Chromosomes to avoid loss of genetic material w/ duplication
EUKARYOTES ONLY
What are mutations in DNA?
Silent < missense < nonsense < Frameshift
Point mutations:
Transition - Pur to Pur or Pyr to Pyr
Transversion - Pur to Pyr or Pyr to Pur
What is a clinical example of a missense mutation? Frameshift mutation?
Missense - nuc substitution yields new AA in protein
- ex. Sicke Cell Disease substitution of Glu w/ Val
Frameshift - deletion or insertion that changes 3 aa frame for codons
ex. Duchenne Muscular Dystrophy
When does Nucleotide Excision Repair occur? Disease associated?
G1 Phase of Cell cycle
repairs bulky-helix distorting lesions w/ Endonucleoases
Xeroderma Pigmentosum!!!! prevents repair of pyrimidine dimers from UV light bc defective NER
When does Mismatch repair occur? Clinical disease w/ deficiency?
recognize newly synthesized strand and mismatched removed and resealed
G2 phase of cell cycle
HNPCC!!!!!!
What are 2 diseases w/ mutation in Non-homologous end joining?
Ataxia Telangiectasia
Fanconi Aneima
What direction is RNA/DNA and Protein synthesis made in?
DNA and RNA made in 5’ –> 3’ and 5’ end has Triphosphtae for energy
Protein Syntesis is N to C
mRNA to protein is read 5 to 3
Eukaryotic RNA polymerases - what are they and what do they do?
1 = rRNA - most numerous
2 = mRNA - massive
3 = tRNA - tiny
No proofreading funciton
RNA Pol 2 opens DNA at promoter site
What gets added to molecules so that they are trafficked to lysosomes? When does this go awrdy?
Mannose-6-Phosphate added in Golgi to proteins that go to lysosomes
I CELL DISEASE = inherited lysosomal storage disorder
- defect in N-actylglycosaminyl-1phosphotransferase –> Failure of Golgi to phosphorylated mannose resudese on glycoproteins so they are excreted extracellulary instead of delivered to lysosome
Coarse Facial Features, Clouded Corneas, Restricted joint movement an hihg plasma lysosomal enzymes
What are immunohistochemical stains for intermediate filaments?
Vimentin - CT
DesMin - Muscle
Cytokeratin - epithelial
GFAP - neuroGLIA
Neurofil - neurons
Drugs that act on Microtubules?
Microtubules Get Constructed Very Poorly
Mebendazole
Griseofulvan
Colchicine
Vincristine/Vinblastine
Paclitaxel