What are the three stop codons?

A codon consists of a sequence of three consecutive nucleotide bases that together form a unit of genetic code in a DNA or RNA molecule. Codons are named according to the order of their bases.

The three stop codons in mRNA are UAA, UAG, and UGA, where U stands for uracil, A for adenine, and G for guanine. Stop codons provide an end point for protein synthesis. They do not encode any amino acid. The ribosome pauses and falls off the mRNA. Stop codons are also called nonsense or termination codons.

There is only one start codon known as AUG. This start codon marks the beginning of a protein. The stretch of codons between the start codon and a stop codon is called an open reading frame.