Question

Amino acid acceptor arm of tRNA lies at

• A. 3’ end
• B. 5’ end
• C. DHU loop
• D. $T\Psi C$ loop

Answer 1

The correct option is A 3’ end

tRNA has 4 arms.
1. arm with $T\psi C$ loop which has Pseudo-uridine and ribothymidine nitrogen bases. It is the site for attachment to ribosomes.

2. Arm with DHU loop has Dihydrouracil base and it is site for attachment of enzyme aminoacyl synthetase.

3. Arm at 3’ end with a CCA sequence which is amino acid acceptor site.

4. Arm opposite to amino acid acceptor site which has an anticodon loop made up of 3 nitrogen bases which helps in identifying codon on mRNA.