What is the role of the 3' end of tRNA?

The 3' end of tRNA is where the amino acid is attached, enabling the tRNA to transport it during protein synthesis.

The 3' end of the transfer RNA (tRNA) molecule plays a crucial role in protein synthesis, a process that is fundamental to all living organisms. This end of the tRNA molecule is where the amino acid is attached, a process known as aminoacylation or charging. This attachment is facilitated by a specific enzyme called aminoacyl-tRNA synthetase. Each tRNA molecule is specific to one amino acid, and the correct pairing is ensured by the synthetase enzyme.

The 3' end of the tRNA has a conserved sequence, typically reading 'CCA', where the amino acid is attached to the adenine (A) nucleotide. This attachment forms an ester bond, which is a high-energy bond. This energy is later used in the formation of peptide bonds during the process of translation, where the genetic code is translated into a sequence of amino acids to form a protein.

Once the tRNA is charged with its specific amino acid, it is transported to the ribosome, the site of protein synthesis. Here, the anticodon loop of the tRNA pairs with the corresponding codon on the messenger RNA (mRNA) molecule. This ensures that the correct amino acid is incorporated into the growing polypeptide chain. The amino acid is then detached from the tRNA at the 3' end, allowing the tRNA to leave the ribosome and be recharged with another amino acid.

In summary, the 3' end of the tRNA molecule is vital for protein synthesis. It is where the amino acid is attached, enabling the tRNA to transport the amino acid to the ribosome. Here, the amino acid is detached and incorporated into the growing protein chain. Without this function, the correct sequence of amino acids could not be ensured, and protein synthesis could not occur.