Tryptophan is an amino acid necessary for E. coli survival and growth. E. coli contain genes coding for enzymes that synthesize
tryptophan. These genes are grouped together on a segment of DNA called the tryptophan (trp) operon. Cells can use these enzymes to synthesize tryptophan when it is not present in the environment. However, when tryptophan is already present in the environment, cellular resources are shifted away from manufacturing the enzymes for tryptophan synthesis. Tryptophan binds with and activates the trp repressor, which then binds to the trp promoter and blocks RNA polymerase. Blocking RNA polymerase decreases the normal transcription rate of the operon. The tryptophan (trp) operon consists of a promoter, an operator, and 5 trp genes. What type of regulation does the trp operon exhibit? protein modification positive regulation negative regulation translational regulation
In the trp operon, tryptophan binds to the repressor protein, then this complex binds to operator effectively blocking gene transcription preventing the production of enzymes that aids in the synthesis of tryptophan. This happens when high levels of tryptophan is detected. This, it is a repressible/negative type of regulation.
When water turns from a liquid phase in the oceans to gas (water vapor) in the atmosphere, this is called evaporation. When the water vapor (gas ) cools in the cooler upper atmosphere to water droplets (that form clouds), this is called condensation. Evaporation is an endothermic process while condensation is an exothermic process.
