Transcription and RNA Flashcards
(44 cards)
Changes in gene expression
- response of cells due to environmental changes
- regulation of cell cycle
- distinct activities of multitude of differentiated cell types.
- cell differentiation and development
Promoters
DNA sequence to initiate and regulate the rate of transcription of a gene
RNA polymerase
enzyme, synthesis of RNA from DNA template
Differences of eukaryotes to pro (gene expression)
- chromatin
-Compartmentalization in nucleus - Extensive RNA processing
RNA polymerase 1-3
mRNA
template for protein synthesis,
uses polymerase II
rRNA
component of ribosomes, uses polymerase I
tRNA
serve as adaptor molecules that align amino acids along the mRNA template. uses polymerase III
DNA sequence element
denotes a specific short sequence of DNA base pairs within a gene promoter
Cis-acting DNA sequences (promoter)
Regions of non coding DNA that regulates expression of genes
Basal or core promoter
genes transcribed by RNA polymerase II that includes TATA box and an initiator DNA sequence.
Upstream promoter and enhancers
transcriptional regulatory sequences located at sig. distance from promoter. impacts when and how much trancsctiption will occur
Transcription factors
proteins required to for RNA polymerase to initiate transcription.
reporter gene (adjacent to regulatory sequence)
reports on the activity of gene regulatory sequence or promoter
Position of enhancer
functions in any orientation or position relative to the promoter
Initiation
process leading to RNA polymerase II beginning to synthesize mRNA
Elongation
process of synthesizing a mRNA complementary to the coding strand of the DNA
General transcription factors
initiate transcription but does not allow for much transcription to occur
Gene specific factors
reponsible for regulating transcription rate of basal transcription complex
DNA methylation
one of the two parental alleles of genes is expressed during embryotic development
Pre-mRNA
primary transcript that is processed to form mRNA
Processing of mRNA
Capping
polyadenylation
splicing
7 methylguanosine cap
added to pre-mRNA, at 5’end of transcript.
Polyadenylation
process of adding a poly-Adenine tail to pre-mRNA. AAUAA (polyadenylation signal on mRNA)
Splicing
process of removing introns