In the context of proteins and amino acids, "R" refers to the R group, also known as a side chain. This side chain is unique to each of the 20 common amino acids and confers specific chemical properties to that amino acid (Reference: R group).
Understanding R Groups
- Diversity: Each amino acid has a different R group.
- Functionality: These R groups determine the amino acid's characteristics, such as whether it's polar, nonpolar, acidic, or basic.
- Protein Structure: R groups play a crucial role in protein folding and overall protein structure, as interactions between different R groups influence how the protein twists and bends.
Examples of R Groups and their Properties
| Amino Acid | R Group | Properties |
|---|---|---|
| Glycine | -H | Nonpolar |
| Alanine | -CH3 | Nonpolar |
| Serine | -CH2OH | Polar |
| Cysteine | -CH2SH | Polar |
| Aspartic Acid | -CH2COOH | Acidic |
| Lysine | -(CH2)4NH2 | Basic |
The properties of these R groups influence how proteins interact with other molecules and carry out their functions.
