Introduction to Bio 3 Flashcards
What is the function of dna
information storage
What is the function of RNA
Genetic message = mRNA Adaptor = tRNA Structural RNA = Xist Catalyst = ribosome (rRNAs) Spliceosome (snRNAs) Guide RNAs: -snoRNAs -CajalRNAs -microRNAs -telomerase
What is the general principle for transcription of RNA
trans-acting factors bind to cis-acting promoter
RNA polymerase binds to this complex (unable to bind to promoter)
What is used in RNA transcription
DNA used as template
Complementary to one strand
RNA polymerase (acts 5 to 3)
not as accurate as DNA replication
Tell me about enhancers
- short DNA sequences
- positive regulative element
- position and orientation independant
-Bind everywhere and cell type specific transcription factors - Stabilise transcription machinery assembly by protein-protein interactions
OPPOSED BY SILENCERS
What are the two domains of transcription factors
DNA binding domain
Activation domain
Why must mRNA be processed
protect from exonuclease
Aid support
identify as mRNA
the sequence of information within genes and amino acid sequence of proteins were known to be
co-linear
What is the case in most individuals in regards to consistency
sequence within genes wont be touching
interrupted gene
introns
do not encode protein
axons
do encode protein
Tell me about splicing through two esterification reactions
Lariat structure
determined by sequences around each intron/exon junction
Spliceosome contains snRNA
Splicing and alternative splicing
Exon order is always maintained
variant transcripts
different protein isoforms
what are the different types of polymerase and what are their functions
polymerase 1 - transcription of rRNA
polymerase 2 - protein coding rna
polymerase 3 - transcription of tRNA
polymerase 2
has a dna motif TATA (tend to be found in the minor groove)
if TBP binds it distorts the DNA
facilitating the binding of RNA polymerase and transcription factors
