10-Gene Regulation Flashcards
What is an operon?
Is a cluster of genes with related functions,
including the control sequences
What are the control sequences?
Are stretches of DNA that coordinate gene
expression.
What is a promoter?
-Is a control sequence.
-Is the site where the transcriptional
regulatory proteins/enzyme initiates
transcription.
What is an operator?
An operator -Is a DNA sequence between the promoter and genes they regulate. -Acts as an “on” and “off” switch for the genes.
WHixh enzyme does the E.coli make in the presence of lactose and which is the name of the gene that is coded form?
=In the presence of the sugar lactose, E. coli makes
an enzyme called beta galactosidase
- Beta galactosidase breaks down the sugar lactose
so the E. coli can digest it for food - It is the LAC Z gene in E coli that codes for the
enzyme beta galactosidase
What is a repressor
E. coli regulates the production of Beta Galactocidase
by using a regulatory protein called a repressor
Where does the repressor bind to?
-The repressor binds to the lac Z gene at a site
between the promotor and the start of the coding
sequence
- The site the repressor binds to is called the operator
What is the trp operon and what does it consist of?
Its another operon that codes compartments for production of tryptophan
It consists of 5 structural genes that encode tryptophansynthase
- trp A
- trp B
- trp C
- trp D
- trp E
What is trp R?
It is the repressor gene for the trp operon.
Where transcription factors are bound?
They are bound to sequences called enhancers
Where repressor proteins are bound to?
They are bound to DNA sequences tha are called silencers
What is Histone Acetylation?
It is the process when the dna is loosened before transcription takes place, as it is tightly wrapped.
Deacetylation is the opposite process.
