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.
I think the organisms in that ecosystem would most likely have an problem in there ecosystem because if any animal adapted to that environment they would most likely be already adapted to that environment
Answer:
C. This is an example of VNTRs.
Explanation:
VNTRs are Variable Number Tandem Repeats. These are short sequences of DNA repeated in tandem (that is, the sequences are repeated one next to the other) a certain number of times. Unrelated individuals have a different number of repetitions for a certain region of the DNA, therefore the total length of the fragment is variable among individuals, depending on how many times the short sequence is repeated.
Answer: C
Explanation:
LD50 is a measure of toxicity in animals. A chemical with a smaller LD50 is more toxic and in this question, Shiga toxin has a lower LD50, thus it is more lethal.
C eastern Europe
Mostly near the baltics and the Balkans, but Czech is also a slavic language.
