Q.What is a codon?
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Start your 14-day free trial to unlock the full solution →A codon is a three-nucleotide "word" in mRNA that the ribosome reads to add one specific amino acid to the growing polypeptide chain.
Proteins are built from a sequence of amino acids, but mRNA carries its information as a linear sequence of just four different nucleotide bases (A, U, G, C). To specify the 20 different amino acids used in proteins, the genetic code groups these bases into non-overlapping triplets - each set of three consecutive nucleotides is a CODON. Since there are 4 bases, the possible triplet combinations number 4x4x4 = 64 codons, more than enough to code for all 20 amino acids (with most amino acids specified by more than one codon - the code is described as "degenerate"). Of these 64 codons, one (AUG) also serves as the START codon (marking where translation begins, and …
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