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Flashcards in More molecular biochem Deck (16)
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1
Q

Xeroderma pigmentosum defect

A

nucleotide excision repair. pts cn’t repari pyrimadine dimers that form d/t UV light exposure

2
Q

Hereditary nonpolyposis colorectal cancer defect

A

mismatch repair defect.

3
Q

ataxia telangiactasia defect

A

ATM gene defect. mutation results in poor non-homologous end joing after double stranded breaks

4
Q

mRNA processing in the nucleus

A

capping of 5’ end, polyadenylation of 3’ end, splicing of introns

5
Q

alpha amanitin

A

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

6
Q

mRNA quality control

A

occurs at cytoplasmic P bodies.

they contain exonucleases, decapping enzymes, and microRNAS.

7
Q

Significance of autoantibodies to splicesomal snRNPs (small nuclear ribonuclear proteins) and autoantibodies to U1RNPs

A

Anti-smith antibodies are highly specific for lupus (splicesomal snRNPs), antibodies against U1RNPs are specific for mixed connective tissue disease

8
Q

tRNA structure

A

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)

9
Q

Important energy molecules used in protein synthesis

A

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

10
Q

Rough ER: function, specialized types

A

make proteins for secretion. Also does N-linked oligosaccharide addition. in neurons, the RER is called a Nissl body. Nissl bodies synthesize neurotransmitters.

11
Q

Smooth ER function

A

makes steroid synthesis and detoxification of drugs and poisons.

12
Q

Function of Golgi

A

modified N-oligosaccharides on asparagine. Adds O oligosacchraides on serine and threonine. Adds mannose-6-P for trafficking of proteins to lysosomes

13
Q

I cell disease

A

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.

14
Q

COPI vs COPII

A

trafficking proteins. COPI is retrograde. within the Golgi and golgi to ER.
COPII: anterograde. Golgi-Goli anterograde; ER to Golgi

15
Q

What is digested in the peroxisome?

A

very-long-chain fatty acids, branched chain fatty acids, amino acids

16
Q

What disease is associated with defective proteosomes?

A

Parkinsons