Answer:
a-atmosphere
Explanation:
atmosphere is a body of gases located on a planet or other materials
When translated:
In that sense, in a sense,
Answer:
The microbes thriving in acidic environments are termed as acidophiles, and these range from eukaryotes to bacteria and archaea, which are mainly found in diverse acidic surroundings like sulfuric geysers and pools, in the human stomach, and in the regions that get polluted by acid mine drainage.
The mentioned case is not entirely correct as the protons found in the acidic surroundings are not utilized for the generation of ATP as they are not originating from within the cell. In order to sustain their internal acidic pH, the acidophiles exhibit adaptations like the presence of the negatively charged proteins on the surfaces of their membranes so that they can prevent deterioration due to acidic surroundings.
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.
