<Tr> <Th> Ambiguous amino acids </Th> <Th> 3 - letter </Th> <Th> 1 - letter </Th> <Th> </Th> </Tr> <Tr> <Td> Any / unknown </Td> <Td> Xaa </Td> <Td> X </Td> <Td> All </Td> </Tr> <Tr> <Td> Asparagine or aspartic acid </Td> <Td> Asx </Td> <Td> </Td> <Td> D, N </Td> </Tr> <Tr> <Td> Glutamine or glutamic acid </Td> <Td> Glx </Td> <Td> Z </Td> <Td> E, Q </Td> </Tr>

Explain how one specific type of isomers (e.g. l-amino acid) can be functional in living organism