trp operon

An amino acid that can be absorbed from the environment or synthesized by the cell:

Trp ( tryptophan)

Trp Operon : ___________ with 5 genes encoding enzymes required for ________ synthesizing Tryptophan

Repressible operon; synthesizing

Trp R : encoded the trp ________ protein which is expressed in the _______ form

Repressor; inactive

Insctive TrpR protein requires a ________ usually _____ in order to bind the operator

Co-repressor; Trp

Inactive trp Recessor & tryptophan =

Active trp Repressor

When Tryptophan is abundant the cell does not need to synthesize its own & the trp operon is ___________

Inactive

Cellular tryptophan __________ the trp operon when its readily abundant for the cell

Co-represses

Why does the cell synthesize its own enzymes from the trp operon ?

Tryptophan is not readily available

When cellular Tryptophan levels are low and the TrpR remains ________ allowing for ___________.

Inactive; Transcription

Under what conditions does the trp repressor block transcription of the trp operon ?

When the repressor binds to tryptophan

If the trp regulatory gene mutates so that the repressor protein can no longer bind to tryptophan what will be the result?

The trp operon will be continuously expressed

In the absence of tryptophan, ___________:

The inactive repressor cannot bind to the operator so trp operon transcription occurs

Is the creation of tryptophan expensive to the cell ?

Yes, tryptophan is the co-repressor of the trp operon