What primarily dictates the sequence of amino acids in a protein?

The sequence of amino acids in a protein is primarily dictated by the sequence of nucleotides in mRNA. During the process of transcription, DNA is transcribed into mRNA, which carries the genetic information required for protein synthesis from the nucleus to the ribosomes where translation occurs.

In translation, the ribosomes read the mRNA sequence in sets of three nucleotides, known as codons, which correspond to specific amino acids. This codon-anticodon pairing is facilitated by transfer RNA (tRNA) molecules, each carrying a specific amino acid and having an anticodon that pairs with the mRNA codon. Therefore, the information encoded in the mRNA translates directly into the linear sequence of amino acids, forming the polypeptide chain that folds into a functional protein.

Considering the other options, while tRNA structure is important for the specific pairing with mRNA codons, it is ultimately the mRNA sequence that determines the overall amino acid sequence. Ribosomal RNA (rRNA) contributes to the structural and functional aspects of ribosomes but does not dictate the amino acid sequence directly. Lastly, integrins, which are proteins involved in cell adhesion and signaling, do not have a role in determining amino acid sequences in proteins.

Thus