Gene Expression in Bacteria Flashcards
Inducible gene expression
induced by certain environment
constitutive gene expression
continuous expression
repressible gene expression
gene end product represses gene expression
what level are genes regulated in prokaryotes
protein-DNA interactions
operon definition
cluster of genes that encode proteins with related functions
two types of prokaryotic gene expression
negative control: expression occurs unless shut off by regulator
Positive: expression occurs only if stimulated by regulator
main function of lac operon in E. coli
producing 3 polypeptides needed for use of lactose
what is an inducible operon system
system that is under both positive and negative control
role of repressor gene in lac-operon
regulate the gene expression by changing shape and chemical activity
how does negative control in lac-operon model work in presence and absence of lactose
lactose: lactose triggers gene expression of glucose(positive control)
no lactose: works with glucose(negative control)
why is tryptophan operon considered a repressible system?
the repressor is normally inactive
how does tryptophan operon differ from lac-operon
end product represses function in TRP operon
role of leader and attenuator in tryptophan operon
regulate activity of TRP operon based of TRP concentration in the cell
role of tryptophan in TRP operon system
presence of tryptophan activates the repressor
