Gene control Flashcards
(13 cards)
What are the 3 type of regulatory mechanisms?
- regulation at transcriptional level
- regulation at post-transcriptional level
- regulation at the post-translational level
What is a regulatory gene?
These code for proteins which control the expression of structural genes
what is the lac operon?
Found in bacteria, the lac operon controls the production of the enzyme lactase
What does a structural gene do?
These code for a protein which have a function in the cell (eg enzymes)
what is an operon?
A group or cluster of genes that are controlled by the same promoter
What does lactase do?
Lactase breaks down the substrate lactose so it can be used as an energy source in bacteria
What is an inducible enzyme?
An enzyme only synthesised once the substrate is present
What are the components of the lac operon?
promoter, operator, lacZ, lacY, lacA.
What is the lac repressor protein?
A binding site which inhibits the expression of genes coding for proteins involved in the metabolism of lactose
What happens when lactose is absent?
What happens when lactose is present?
