Amino acids coding for

Was this youT answeT A codon is a triplet of mRNA nucleotides holding instructions for the building of a polypeptide strand, and so this sequence contains seven codons. The first andlast are start/stop instructions, however, and so the number of amino acids coded for is only five. The sequence is Leu-Lys-Ser-Gl n-Al a. 

ROD Amino acid code for arginine-glycine-aspartic acid... 

Although more than 700 different amino acids are known to occur naturally, the group of 20 called the standard amino acids listed in Table 25.1 (pages 1120-1121) commands special attention. These 20 are the amino acids coded for in DNA-directed protein synthesis. All are a-amino acids, and all but one contain a primary amino function. 

For the 15 amino acids coded for by two, three, or four triplets, it is only the third letter of the code that varies. For example, glycine is coded for by the triplets GGA, GGG, GGC, and GGU. 

Compare the amino acids coded for by the codons with a pyrimidine, either U or C, as the second base. Do the majority of the amino acids specified by these codons have hydrophobic or hydrophilic side chains ... 

For the 15 amino acids coded for by two, three, or four triplets, only the last base of the triplet varies. 

J. Rumbley, L. Hoang, L.Mayne, and S. W. Englander, An amino acid code for protein folding. Proc. Natl. Acad. Sci. USA 98, 105-112 (2001). 

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