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.
All the important functions of our body would simply be too slow for us to survive such as digestion. if we didn't digest quick enough our stomachs would be bloated all the time
The CNS involves the brain and spinal cord and the PNS involves the body nerves.
Answer:
A. to conserve soil nutrients
Explanation:
Crop rotation helps to maintain soil structure and nutrient levels. If you don't rotate crops, the soil in that field will inevitably begin to lose the nutrients plants need to grow.
D. metamorphic -> melting -> igneous -> erosion
Explanation:
The sequence that would be the best possible for a rock going through the rock cycle is metamorphic rocks melting to produce igneous rocks that are eroded.
- The rock cycle shows the pathway by which different rock types are formed.
- The origin of the formation of rocks starts with the production of magma.
- Igneous rocks are formed from cooling and solidification of molten magma.
- Metamorphic rocks are formed from the subjection of igneous and sedimentary rocks to high temperature and pressure.
- Sedimentary rocks are formed from weathering, erosion, transportation and deposition of rocks.
- Option D shows a metamorphic rock melting to give igneous rocks and the igneous rock is eventually eroded to form sedimentary rocks.
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Sedimentary rocks brainly.com/question/2740663
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