Since there are 64 possible codons and only 20 amino acids, many amino acids are represented by multiple codons. For example, GCA, GCC, GCG, and GCT all code for the amino acid alanine.

The 64 possible codons (4 3) are divided between encoding the 20 amino acids as well as a stop signal. Thus, only 21 of the 64 possible codons are required to make a comprehensive code.

The genetic code therefore has 64 possible codons (four nucleotide possibilities at each of the three positions in a codon). Among the 64 codons, 61 are sense codons, each of which specifies 1 of ...

A central tenet of biology may need updating given new measurements of start codons. For decades, scientists working with genetic material have labored with a few basic rules in mind. To start ...

After all, even if life needed to expand its repertoire of 20 amino acids, there’s still lots of room within the existing 64 codons to do so. Triplet codons work well on Earth, but it’s not clear if ...

“A four-letter alphabet gives you 64 possible codons, which yield 20 amino acids, the building blocks of proteins. Six letters takes you up to 256 codons; eight makes it 4,096. ...

Because there are 64 possible codons but only 20 amino acids, many of the codons are redundant. For example, four codons can each stand for glycine: GGT, GGC, GGA, and GGG.

As BBC News’ Roland Pease writes, the E. coli genome’s use of 61 out of 64 possible codons leaves three open for reprogramming, opening the doorway for “unnatural building blocks” capable ...

These codons can also tell a cell when to start or stop building more amino acids. Now with just three spots and only four different types of nucleotides—which are the genetic letters A, T, G ...

Messenger RNA has 64 possible triplet sequences, or codons, three of which usually terminate protein synthesis. But some organisms can use all codons to specify amino acids, thanks in part to a ...