A difference between a Class I and a Class II tRNA synthetase is (select all that apply): a. the Class I synthetase reaction requires a transesterification reaction not necessary in the Class II reaction.
b. the Class I synthetase uses the 2' OH of the 3' end of the tRNA as a nucleophile and the Class II uses the 3' OH.
c. the Class I synthetase requires ATP as a cofactor and the Class II does not.
d. the Class II synthetases are typically monomeric, whereas the Class I enzymes frequently function as multimeric protein complexes.

Option b is the correct answer.

Explanation:

The 2' OH of each 3' end of the tRNA is used as a nucleophile by Class I synthetase, whereas the 3' OH is used by Class II.

The Class I aminoacyl-tRNA synthetase attaches amino acids to the 2'-OH group of the tRNA's 3'-end ribose residue, whilst the Class II synthetase attaches amino acids only to the 3'-OH group of the tRNA's 3'-end ribose residue. Both Class I and Class II enzymes conduct the transesterification process and the need of ATP.

What we have is option d is incorrect because, Class I enzyme is typically monomeric, while the Class II enzyme is dimeric or multimeric in nature.

surface mining destroys mountain tops, landscapes, forests and wildlife habitats. on top of that, it leads to soil erosion and destruction of agricultural land. the landscape changes can also disrupt river channels and streams, which leads to flooding. which, can destroy plant life and other animals as well.

explanation: