Answer:
The ability of sequences within the leader mRNA to pair with one another and form stem-lopp structures
Explanation:
A form of feedback regulation controls the trp operon by regulating transcription termination, a mechanism referred to as Attenuation.
-In the presence of high concentrations of tryptophan, RNA polymerase ceases transcription shortly after initiation in a region called the leader sequence.
-If the concentration of tryptophan is low, transcription does not terminate until the entire operon is transcribed. The mechanism of attenuation links alternative RNA secondary structures to transcription termination.
-Immediately after transcription, RNA from the leader region folds into one of two alternative secondary structures.
-One of these structures is a transcription termination signal that stops RNA polymerase from continuing to the end of the operon.
-The alternative structure does not contain a transcription termination signal and allows transcription of a single mRNA that encodes all the structural genes.
-The decision as to which of the two alternative RNA structures formed is regulated by the concentration of tryptophan.
Answer:
When a cell is very low on ATP, it will start squeezing more ATP out of ADP molecules by converting them to ATP and AMP (ADP + ADP → ATP + AMP).
The answer is A. Differentiation
Iron, oxygen and water react with the iron creating a substance known to us as rust.
Hope this helps.
Mutualism. e.g. oxpecker and zebra
commensalism. e.g. remora fish and sharks
parasitism. e.g. tapeworms and cow
