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.
Answer:
correct answer is A
Explanation:
nucleus is most important part of a cell as a town hall would be to a city
Answer:
A. A majority of scientists agreed with it
Explanation:
The famous theory called the theory of common descent, states that all the living organisms of the earth have arisen from a common ancestor. This notion was first proposed by a French mathematician,Louis Maupertuis duirng 1740s who was of the view that all organisms had a single ancestor and evolutionary process with the passage of time resulted in the specie diversification.
After that, in 1790s another philosopher Immanuel Kant, suggested that all organisms seem to have a common ancestor. In the same period of 1790s, another scientist , Erasmus Darwin who was the grandfather of Charles Darwin also suggested that all the organisms might have a single ancestor who went through the process of evolution to bring all the majesty into life.
Charles Darwin was the first scientist who worked on this notion for alot of time and proposed the theory of common descent,in his book, On the Origin of Species.
After it, many scientists got agree with this theory such as, Vernon Kellogg in 1907 and T. Ryan Gregory in 2008 and many others explain that no reliable observations exists which contradicts the theory of common descent.
Therefore, option A is the best option.
Hope it helps!
Answer:
Están interconectados entre sí.
Explicación:
Existe una relación directa entre los intereses, las necesidades y las aspiraciones de la adolescencia porque todos están interconectados entre sí. Como adolescente, nuestro interés es lograr el éxito en la vida especialmente en el campo de la educación y adquirir la profesión que nos es favorita. Como adolescente, nuestras necesidades son buena comida, ropa, un hogar para vivir y una educación adecuada.
Designing and constructing buildings that are made of recycled materials, energy efficient, and economical, is a trend called<span> Green architecture.</span>
