Explanation
In examining several amino acids, the amino acid group will remain same the difference will be generated by the 'R' group attached to the chain.
'R' group can be :
- Single long chain of carbons with saturated carbon-carbon bond.
- Single long chain with unsaturated carbon-carbon bond Including aromatic carbon rings.
- Branched chain with saturated carbon-carbon bond
- Branched chain with unsaturated carbon-carbon bond.
- Presence of any other atoms like : sulfur, oxygen, phosphorus etc.
For example: alanine and methionine are different amino acids. since the amino acid part is same but the only difference in them is in alanine [tex]CH_3[/tex] group is present as a 'R' group whereas in methionine long unbranched carbon chain with sulfur atom is present as a'R' group.
