stop codon

genetics

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July 16, 2026

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In genetics, a stop codon is a sequence of three adjacent nucleotides that signals the termination of translation, the process of protein synthesis. These codons, along with others that specify amino acids, form the genetic code. There are 64 possible codons, made from combinations of adenine (A), guanine (G), cytosine (C), or uracil (U) in RNA. Of these, 61 code for the 20 amino acids that build proteins, while three act as stop signals: UAG, UAA, and UGA. When a ribosome encounters a stop codon, it triggers the release of the newly synthesized protein.123

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mutation
Some base-pair substitutions produce a stop codon. Normally, when a stop codon occurs at the end of a gene, it stops protein synthesis, but, when it occurs in an abnormal position, it can result in a truncated and nonfunctional protein. Another type of simple change, the deletion or insertion of…
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Some base-pair substitutions produce a stop codon. Normally, when a stop codon occurs at the end of a gene, it stops protein synthesis, but, when it occurs in an abnormal position, it can result in a truncated and nonfunctional protein. Another type of simple change, the deletion or insertion of…
Read More