regulation of transcription and translation Flashcards
what is transcription
when a gene is copied from DNA into messenger RNA
what is the enzyme responsible for synthesising mRNA from DNA
RNA polymerase
the transcription of genes is controlled by protein molecules what are these called
transcription factors
what is a transcription factor
a protein molecule that controls the transcription of a gene
where do transcription factors in eukaryotes move from and to
moves from the cytoplasm to the nucleus
what do the transcription factors in the eukaryotes bind to
specific DNA sites called promoters
where are promoters found
near the start of their target genes - the genes that they control the expression of
what is a promoter region
a DNA sequence that tells the enzyme RNA polymerase where to start producing mRNA
some transcription factors are called activator what do they do
stimulate/increase the rate of transcription
other transcription factors are called repressors what do they do
inhibit/decrease the rate of transcription
give an example of a steroid hormone
oestrogen
how can oestrogen affect transcription
by binding to a transcription factor called an oestrogen receptor forming an oestrogen-oestrogen receptor complex
where does the oestrogen-oestrogen complex move from and where does it move to
moves from the cytoplasm and into the nucleus
what happens when the oestrogen-oestrogen complex gets to the nucleus
binds to specific DNA sites near the start of the target gene
what can the oestrogen-oestrogen complex act as
an activator of transcription
what else is gene expression also affected by in eukaryotes
RNA interference
what does RNAi stand for
RNA interference
what is the abbreviation for RNA interference
RNAi
what is RNA interference
where small, double stranded RNA molecules stop mRNA from target genes being translated into proteins
what are the two molecules involved in RNAi
siRNA and miRNA
what does siRNA stand for
small interfering RNA
what does miRNA stand for
microRNA
what happens in plants when mRNA has been transcribed
it leaves the nucleus for the cytoplasm
what happens in plants in the cytoplasm
the double stranded siRNA associates with several proteins and unwinds
