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. owever, 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. What type of regulation does the trp operon exhibit?a. positive regulation b. protein modification c. negative regulation d. translational regulation
The correct answer is - The tryptophan operon shows C. negative regulation.
Explanation:
Tryptophan is an amino acid, excessively synthesized by the organism, it regulates its transcription through “trp Operon.” In this operon, the corepressor of the tryptophan binds to the repressor protein and gets activated.
This activated repressor now binds to the operator site, and prevents the binding of RNA polymerase enzyme and inhibits the protein synthesis.
The pollen grain is creating a tube down the style of the flower. <u>It is necessary as that is how the pollen is able to travel down the style into the ovary where the baby seed is located. This is how the seed is fertilized, and is ready for reproduction.</u>
