The R-Group, otherwise known as the side chain, is the variable functional group on the alpha-carbon atom of an amino acid that determines it's function. The R group can determine the amino acid's charge and polarity It is very precise and specific for each different amino acid. All 20 amino acid's have a different R group. If a change in the structure of the side chain occurs then this could change the function of that amino acid.
- ↑ Stryer et al. (2011) "Biochemistry 7th ed, glossary" available at: http://bcs.whfreeman.com/berg7e/#644431__697011__fckLRlast accessed: 30/11/12
- ↑ Stryer, L., Berg, J.M., Tymoczko, J.L, (2011) "Biochemistry" 7th ed. pg 27-28, New York: Freeman and Company