Answer:
(C) Aminoacyl-tRNA synthetases have an additional active site that binds to non-cognate tRNAs. The tRNAs that bind to this second active are hydrolyzed and released from the enzyme.
Explanation:
In case of translation, proof reading is done by aminoacyl-tRNA synthetases only. Aminoacyl-tRNA synthetases have two mechanisms to avoid error during translation which are mentioned as under:
<u>(1) Chemical proof reading:</u> Incorrect amino acids rather than being hydrolyzed in catalytic pocket get hydrolyzed in editing pocket and thus they hardly get attached to tRNA.
For example: For distinguishing similar amino acids like isoleucine and valine, isoleucyl-tRNA synthetase uses a second active site which is meant for only valine not for isoleucine. In this particular site, valine which had entered the enzyme is cleaved away with the help of editing reaction after which the enzyme is well prepared to process isoleucine which is the correct amino acid for this enzyme.
<u>(2) Kinetic proof reading: </u>Even if an incorrect amino acid has entered a particular aminoacyl-tRNA synthetase, it does not cause appropriate conformational change in the enzyme because of which the incorrect amino acid loosens from the enzyme and does not get incorporated.
Note: In this example, only chemical proof reading is mentioned not kinetic proof reading.
One of the major problems of monoculture farming is the variety of species. If there are no varieties in the producer level in the food chain all other organisms within the ecosystem would be affected.
<span>In
the desert food web shown below, which of the following best describes
the transfer of energy between the lubber grasshopper and the kangaroo
rat?
</span>
<span>C) About 10 percent of the kangaroo rat's energy transfers to the lubber grasshopper.
</span>
Answer: each allele is its own entity and always has an equal chance of being passed on to the next generation
Explanation:
I already learned this and i remember that is why my notes said and i also looked it up.
