The genetic code In DNA and RNA consist of the sequence of
nucleotides. The nucleotides in DNA are adenine (A), guanine (G), cytosine (C), and thymine (T), while in RNA, thymine is replaced by uracil (U). The genetic code is a triplet code, meaning that every three nucleotides (called codons) codes for a specific amino acid or a stop signal. There are a total of 64 different codons, including three stop codons (UAA, UAG, and UGA) that signal the end of protein synthesis.
The sequence of nucleotides in DNA/RNA determines the sequence of amino acids in a protein. Each codon corresponds to a specific amino acid or a start signal, which initiates protein synthesis. This sequence of amino acids determines the structure and function of the protein. The genetic code is universal, meaning that the same codons code for the same amino acids in all organisms, from bacteria to humans. However, some organisms may have slight variations in the genetic code, which are called codon usage biases.