The genetic code is degenerate. Amino acids are encoded by either 1, 2, 3, 4, or 6 triplet...

The genetic code is degenerate. Amino acids are encoded by either 1, 2, 3, 4, or 6 triplet codons. (See Figure.) An interesting question is whether the number of triplet codes for a given amino acid is in any way correlated with the frequency with which that amino acid appears in proteins. That is, is the genetic code optimized for its intended use? Some approximations of the frequency of appearance of nine amino acids in proteins in E. coli are given in the following:

(a) Determine how many triplets encode each amino acid.

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(b) Devise a way to graphically compare the two sets of information (data).

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(c) Analyze your data to determine what, if any, correlations can be drawn between the relative frequency of amino acids making up proteins and the number of codons for each. Write a paragraph that states your specific and general conclusions.

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(d) How would you proceed with your analysis if you wanted to pursue this problem further?

Figure

The coding dictionary. AUG encodes methionine, which initiates most polypeptide chains. All other amino acids except tryptophan, which is encoded only by UGG, are represented by two to six triplets. The triplets UAA, UAG, and UGA are termination signals and do not encode any amino acids.