Question

The amino acid attaches to the .......... end of the amino acid acceptor arm.

• A. 5'
• B. 3'
• C. Bidirectional
• D. None of the above

Answer 1

Answer: (B)

3'

In the cloverleaf model of tRNA, the amino acid arm has seven base pairs stem formed due to base pairing between 5′ and 3′ ends of tRNA. At its 3′ end, a sequence 5′-CCA-3′ is added. This is known as amino acid acceptor arm or CCA arm. During protein synthesis, amino acid binds to this arm. Thus the correct answer is option B.