Why there are only 20 amino acids, although a amino acid is coded by a single codon with three bases. That means by permutation,

Question

miss Akunina [59]

2 years ago

10

Why there are only 20 amino acids, although a amino acid is coded by a single codon with three bases. That means by permutation,

3*3*3=27 amino acids must exist ??? ...?

Chemistry

1 answer:

snow_lady [41] · Answer 1 · 2022-05-30T20:47:31+03:00

In nature there are many more variations amino acids than the simple 20 found in humans. However, when analyzing the human genome sequence, there is a code for all 64 permutations (4^3), only some of them share amino acids. This is a safe-guard against mutations of one or two nucleotides. For example, the amino acid Alanine is coded with four different nucleotide sequences: GCA, GCC, GCG, GCU. Also some amino acids code the same like UUU &UUC