<u>Answer:</u>
<em>The minerals that are formed </em><em>deep beneath the earth surface</em><em> comes to the earth's surface by following two ways.</em>
<u>Explanation:</u>
It can come out in the form of volcano or lava and once cooled will form an igneous rock. It can also come out due to the movement of tectonic plates and can for metamorphic rock.
Basalt and granite are the commonly found minerals. The mineral crystals mostly form rocks. The lava on the surface sometimes gets cool so quickly that it fails to crystallise some minerals.
Answer: 1. mechanical weathering
2. Soil
Explanation:
1. Some animals such as moles dig which breaks down rocks underground.
2. Soil is different amounts of broke down particles some still have big particles like sand while others are really fine like clay.
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.
