The average estimated cash rent was $202 per acre on top quality land, $161 per acre on average quality land, and $124 per acre on poor quality land. This was an increase in rental rates of 2.0% for top quality land, 1.9% for average quality land, and 2.5% for poor quality land.
R-Group. In solution it is the nature of the amino acid R-groups that dictate structure-function relationships of peptides and proteins.
Amino acids are organic compounds which contain both an amino group and a carboxyl group. They are distinguished by the attached functional group R. Of the twenty amino acids that make up proteins, six of them have hydrocarbon R-groups.