...AND will dna and AMINO ACID SEQUENCES BE the only things in ALL CAPITAL letters in your data? What does it mean to "tag it?" How is your table structured?

Perhaps those questions illustrate the inadequacy of your specification.

Perhaps even more important, read about BioPerl, FASTA, and the vast array of other related options, many of which can be found using Google, site:CPAN, and appropriate search terms.

If you're still stuck after that, c'mon back with a more detailed question about some particular part of your project where you still have a problem. We're here to help you learn how to use Perl and its modules, but we need a manageable (and well specified) problem... and greatly prefer to see your efforts and help you overcome stumbling blocks than to simply hand you a solution.