Here's why:
* mRNA carries the genetic code: mRNA (messenger RNA) carries the genetic information from DNA to the ribosomes, where protein synthesis takes place. It acts as a blueprint for building proteins.
* tRNA is the adaptor: tRNA (transfer RNA) acts as an adaptor molecule. It has two key features:
* Anticodon: Recognizes a specific codon (three-nucleotide sequence) on the mRNA.
* Amino acid binding site: Binds to the specific amino acid that corresponds to the codon.
* Ribosomes facilitate the process: Ribosomes are the cellular machinery responsible for protein synthesis. They bind to mRNA and bring together tRNA molecules carrying the correct amino acids, facilitating the formation of a polypeptide chain.
Therefore, the binding process goes like this:
1. mRNA: Carries the genetic code for the protein.
2. tRNA: Binds to a specific codon on the mRNA and carries the corresponding amino acid.
3. Ribosome: Facilitates the binding of tRNA to mRNA and the formation of peptide bonds between amino acids.
So, amino acids are not directly bound to the mRNA. They are brought to the ribosome by tRNA molecules that recognize specific codons on the mRNA.
