1.1.3 Regulating genes : What to make today Flashcards
What is a proteome ?
The proteins produced by an organism , different cells do different things, each cell cannot produce the entire proteome
What is gene regulation?
Cells need to pick and choose which proteins they produce, in what quantities and at what times
What are exons ?
bits of the gene that form the code of the protein
translated
What are introns ?
Introns are the unnecessary uncoding parts. They are removed in RNA processing
What is the promotor ?
The part of the gene that RNA polymerase binds to. The promotor tells RNA polymerase where the gene is and where to begin reading
What is the operator?
It is a region of the gene to which a repressor protein binds
What is a repressor protein?
A protein that inhibits the expression of one or more genes.
What happens when a repressor protein is bound to the gene?
RNA polymerase cannot bind and therefore the gene will not be expressed.
What is an operon?
An operon is a special kind of gene that codes for multiple proteins at once!
Trp operon
Those proteins work together to synthesize the amino acid tryptophan
Explain the Trp Operon
If there is an abundance of tryptophan in the cell - No more needs to be made ( waste of time and resources )
If the cell is low on tryptophan it needs to make more
The Trp Operon involves a mechanism that allows the gene to be expressed when tryptophan is low and switch off when it is high
Cells that have the Trp Operon produce a protein called the Trp repressor. The protein is only active if tryptophan binds to it. When it is active, the repressor will bind to the operator region of the operon . This prevents RNA polymerase and blocks transcription .
