Here's why:

* tRNA (transfer RNA) acts as a molecular adapter, bridging the gap between the genetic code in mRNA and the amino acids that make up proteins.

* mRNA (messenger RNA) carries the genetic code from DNA to the ribosomes, where protein synthesis occurs.

* Amino acids are the building blocks of proteins.

The process works like this:

1. mRNA arrives at the ribosome.

2. tRNA molecules, each carrying a specific amino acid, bind to the mRNA according to the genetic code.

3. The ribosome links the amino acids together in the order dictated by the mRNA, forming a polypeptide chain.

4. This polypeptide chain eventually folds into a functional protein.

So, tRNA is crucial for translating the genetic information in mRNA into the amino acid sequence of a protein.