What is meant by the term "genetic code"?

The term "genetic code" refers specifically to the set of rules that dictate how the information encoded in the sequence of nucleotides within mRNA is translated into the sequence of amino acids in proteins. This code is fundamental to the process of protein synthesis, where groups of three nucleotides, known as codons, correspond to specific amino acids. Each codon in the mRNA sequence is recognized by a complementary tRNA molecule that brings the appropriate amino acid to the growing polypeptide chain.

The genetic code is universal across nearly all organisms, highlighting its fundamental role in biology. The existence of this code explains how genetic information flows from DNA to RNA and ultimately to proteins, which perform a vast array of functions in living organisms. Thus, understanding the genetic code is crucial for molecular biology as it underpins mechanisms such as gene expression and regulation.