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why can't a dna sequence code for more than 1 aa?
- Anonymous1 decade agoFavorite Answer
The short answer: A triplet of base-pairs in a DNA sequence CAN actually code for more than 1 amino acid.
Recall that a protein is assembled piecewise by a ribosome and a series of tRNA molecules floating around it. The DNA sequence is fed into the ribosome 3 base pairs at a time and link up to a tRNA molecule that has 3 matching base pairs hanging off of it. On the other end of a tRNA is an amino acid. Although a triplet of DNA corresponds very specifically to a given tRNA molecule available in the cell, there are different tRNAs that SHARE the same amino acids.
You can fetch a table of corresponding base-pair to amino-acid sequences here: http://www.tritechresearch.com/shop/images/aachart...
SER (Serine) for instance, is an amino acid that is associated with 4 different tRNA molecules, and thus 4 different triplet sequences of DNA that it corresponds with.Source(s): I'm a biologist.