T3M4 Flashcards
Gene expression can be
regulated at
- transcription initiation
- RNA processing
- overall stability of the RNA molecule
- protein synthesis
- protein modifications and transport
- protein degradation
Scientists examine patterns of gene expression of specific genes by
identifying mRNA products that are produced
In-situ hybridization can be utilized to
study the expression of one or a few genes of interest
DNA microarray chips contain
DNA molecules that act as probes to detect gene expression
If a gene is active in the microarray (bright spots)
it will produce many molecules of mRNA, more labelled cDNA molecules available after
reverse transcription which will be able to
hybridize to the DNA on the microarray chip
Relative gene activity measures by
intensity of fluorescence
- more mRNA = more active
To stop gene expression mRNAs should be
degraded
mRNA stability regulated by
length of polyA tail
miRNAs result in
inhibition of translation
miRNAs form
hair pin loops complementary base pairing within precursor transcript, RNA induced silencing complex
siRNAs regulate gene expression
bind to complementary sequence and induce cleavage of RNA
Post-translational modifications that allow for the production of mature and functional proteins
- cleavage
- disulphide bond formation
- acetylation
- phosphorylation
- methylation
Post-translational modifications allow for
cell to activate or inactivate specific proteins
Length of time in which a protein functions in a cell can
be limited by a process called
selective degradation
Proteasomes
very large protein complexes that are found in cells that are able to break peptide bonds and as a result degrade
unneeded or damaged protein
