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.
the minimum amount of energy that is required to activate atoms or molecules to a condition in which they can undergo chemical transformation or physical transport.
Blood vessels that absorb strong pressure pulses contain more of elastic<span> tissues. These tissues are bundles of protein that can be found in extracellular matrix of connective tissue. These are produced by fibroblasts and smooth muscle cells found in arteries. </span>
The effects of weathering disintegrate and alter mineral and rocks near or at the earth's surface. This shapes the earth's surface through such processes as wind and rain erosion or cracks caused by freezing and thawing. Each process has a distinct effect on rocks and minerals.