Question

DNA encodes proteins by reading the sequence in ordered triplets. For example, the three ordered triplets in the ACCAGGTTA sequence are ACC, AGG, and TTA. That is, a different triplet can encode a different amino acid. How many different amino acids can be coded for each ordered triplet?

Answer 1

Answer: There are 20 amino acids possible to be encoded by all combinations of triplet or codons. Out of the possible 64 combinations of codons, 3 of them are stop codons which donot encode for any amini acid and 61 of them specify for different amino acids.

Each ordered triplet of nucleotides is also called as a codon. Every codon, except for the 3 stop codons encode for only a single amino acid which is unique. There are 20 amino acids which are encoded by a 64 combinations of codon or triplet nuclotides. So, an amino acid can be encoded by more than one codon and this is also the reason that the genetic code is said to be degenerate.

Example: A single codon or triplet encodes for only one amino acid i.e UUU encodes for phenyalanine amino acid always.

But, phenylalanine is also encoded by codon UUC. So, an amino acid can be encoded by more than one codon.