Question

Write a short note on transfer RNA (tRNA).

Hint:

Adaptor molecule; clover-leaf shape; anticodon pairs with mRNA codon.

Answer 1

Step 1: Define tRNA:
Transfer RNA (tRNA) is a small, single-stranded adaptor RNA molecule that reads the genetic code on mRNA and carries the corresponding specific amino acid to the ribosome during protein synthesis (translation).

Step 2: Describe its structure:
tRNA folds into a characteristic clover-leaf secondary structure (and an L-shaped tertiary structure), with an anticodon loop that base-pairs with a complementary codon on mRNA, and an acceptor end (3' CCA end) where the specific amino acid attaches.

Step 3: State its role in translation:
Each of the twenty amino acids has at least one specific tRNA; the correct tRNA delivers its amino acid to the ribosome only when its anticodon correctly pairs with the mRNA codon being read, ensuring the amino acid sequence of the protein matches the genetic code.

Final Answer:
tRNA is the adaptor molecule of translation, with a clover-leaf structure carrying an anticodon (to pair with mRNA) at one end and a specific amino acid at the other.