So in biology i was learning about the amino acids and stuff and how like three base pairs make an amino acid. And how there are four types of base pairs. so there would be 64 different types of amino acids (4*4*4) so how come we don't use them all?
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There are not 64 amino acids, there is the potential to use 64, if 64 were available. That is the nature of the genetic code. It evolved to use 3 codons because 2 were not enough. 2 would only code for 16 amino acids. Since we use 20 amino acids, there are 44 extra codons, not 44 extra amino acids. So the extra codons are used as extras for the 20 amino acids, or they are used for stop codons.
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The nature of the residues, their chemical properties combine to produce sufficient shapes to regulate gene expression by protein nucleic interactions and all other protein to molecule functions involved in self reproducing life. There are enough polar, neutral, and charged side chains coming from the few amino acid synthesis pathways.
http://www.scfbio-iitd.res.in/tutorial/g…
Possibly when new amino acids emerge from an altered pathway its costs of manufacturing (negative selection) is stronger than any positive selection for novel protein function.
A degenerate code provides wobble to reduce the cost of single third position nucleotide errors.
http://www.scfbio-iitd.res.in/tutorial/n…
http://www.scfbio-iitd.res.in/tutorial/g…
Possibly when new amino acids emerge from an altered pathway its costs of manufacturing (negative selection) is stronger than any positive selection for novel protein function.
A degenerate code provides wobble to reduce the cost of single third position nucleotide errors.
http://www.scfbio-iitd.res.in/tutorial/n…