Question

Which of the following is incorrect in relation to an adapter molecule $?$

• A. It has an anticodon loop that has bases complementary to the code.
• B. It is also called sRNA.
• C. It has an amino acid acceptor end with which it binds to amino acid.
• D. It shows an inverted L-shaped 2-D structure.

Answer 1

Answer: (D)

$tRNA$ has an anticodon loop which has anticodons complementary to the codons of $mRNA$. Due to very small size, $tRNA$ is also called soluble RNA. Amino acid binds to $3^{\prime }$ end of $tRNA$. The cloverleaf model shows the basic plan of tRNA secondary structure or $2D$ structure. Three-dimensional structure shows an inverted $L-$ shaped configuration.
There are three loops in tRNA:
i) Aminoacyl synthetase binding loop or DHU loop (dihydroxyuridine loop): 1st loop from 5' end.
ii) Ribosomal binding loop with 7 unpaired bases: It is $1^{\text{st }}$ loop from 3' end, also called loop.
iii) Anticodon loop with 7 unpaired bases. Out of the 7 bases in the anticodon loop, 3 bases act as anticodon for a particular triplet codon present on mRNA.