Flashcards in More molecular biochem Deck (16):
Xeroderma pigmentosum defect
nucleotide excision repair. pts cn't repari pyrimadine dimers that form d/t UV light exposure
Hereditary nonpolyposis colorectal cancer defect
mismatch repair defect.
ataxia telangiactasia defect
ATM gene defect. mutation results in poor non-homologous end joing after double stranded breaks
mRNA processing in the nucleus
capping of 5' end, polyadenylation of 3' end, splicing of introns
found in death cap mushrooms. inhibits RNA pol II (makes mRNA). causes severe haptotoxicity if ingested.
recall that RNA pol I makes rRna, and RNA pol III makes tRNA
mRNA quality control
occurs at cytoplasmic P bodies.
they contain exonucleases, decapping enzymes, and microRNAS.
Significance of autoantibodies to splicesomal snRNPs (small nuclear ribonuclear proteins) and autoantibodies to U1RNPs
Anti-smith antibodies are highly specific for lupus (splicesomal snRNPs), antibodies against U1RNPs are specific for mixed connective tissue disease
looks like a T. amino acid is charged on the ACC end (3'). T arm carries the tymine, T-pseudouridine, cytosine sequence for binding to tRNA-ribosome. D arm carries the sequence for recognition by the aminoacyl-tRNA synthetase (dihydrouracil residues)
Important energy molecules used in protein synthesis
ATP required for charging a tRNA (activation)
GTP required for initiation of protein synthesis (initiation factors assemble the 40S subunit with the initiator tRNA. they are released when the mRNA and the ribosomal 60S subunit assemble with the complex). GTP is also used for translocation
Rough ER: function, specialized types
make proteins for secretion. Also does N-linked oligosaccharide addition. in neurons, the RER is called a Nissl body. Nissl bodies synthesize neurotransmitters.
Smooth ER function
makes steroid synthesis and detoxification of drugs and poisons.
Function of Golgi
modified N-oligosaccharides on asparagine. Adds O oligosacchraides on serine and threonine. Adds mannose-6-P for trafficking of proteins to lysosomes
I cell disease
defect in addition of mannose-6-P for trafficking of proteins to lysosomes. causes excretion of lysosomal proteins. symptoms: coarse facial features, clouded corneas, restricted joint movement.
COPI vs COPII
trafficking proteins. COPI is retrograde. within the Golgi and golgi to ER.
COPII: anterograde. Golgi-Goli anterograde; ER to Golgi
What is digested in the peroxisome?
very-long-chain fatty acids, branched chain fatty acids, amino acids