Gene Expression. Flashcards
How many genes do we have within one cell?
25000
How does E.coli metabolise glucose and lactose
They only synthesise lactose metabolising enzymes when only lactose is present.
What is lactose permease?
An enzyme which transports lactose into the cell.
What does beta galactose do?
It converts lactose into glucose and galactose.
What is a lac-operon?
A section of DNA which is responsible for the controlling the expression of lactose permiase and betagalactosidase.
What are transcription factors?
They control gene expression eukaryotes and are DNA binding proteins
(They account for 8% of human genes)
What is a regulatory gene?
A gene which is transcribed and translated to synthesise a repressor protein
What is a promoter gene?
A gene which acts as a binding site for RNA/DNA polymerase.
What is an Operon?
A group of genes that function as a single transcription unit.
What is the operator region?
The region at which the repressor protein binds to.
What is a structural gene ?
A gene which codes for a specific structural protein.
What is a repressor protein?
A protein which binds to the operator region.
What happens when lactose binds to the repressor region?
It changes shape which cases it to unbind to the operator region.
What is a hox gene?
A gene that controls the development of body plans and code for a type of transcription factor.
Alternative definition of a transcription factor.
A protein which can combine with a specific site on a length of DNA and inhibit or activate transcription of the gene.
Structure of hox genes?
They contain homeobox sequences
Function of hox genes?
Involved in regulation of patters of anatomical development in animals fungi and plants.
What is the homeobox region?
The region which codes for the homeodomain
And a DNA binding domain.
What does the conservation of the gene mean?
It evolved a long time ago in deep time
How many clusters do tetrapod’s have?
4
What do hox genes control?
Body plan by encoding for homeodomain proteins that act as transcription factors.
They also control the cell cycle and apoptosis.
