Classification of amino acids based on the polarity of the amino acid side chains
|
|
Table 2-2.
Summary of the functional groups of amino acids and their polarity. |
| Body_ID: None |
| Summary of the functional groups of amino acids and their polarity |
| Body_ID: T002002.50 |
| Amino acids | Functional group | Hydrophilic (polar) or hydrophobic (apolar) | Examples |
| Body_ID: T002002.100 |
| acidic | carboxyl, -COOH | polar | Asp, Glu |
| Body_ID: T002002.150 |
| basic | amine, -NH2 | polar | Lys |
| Body_ID: T002002.200 |
| | imidazole | polar | His |
| Body_ID: T002002.250 |
| | guanidino | polar | Arg |
| Body_ID: T002002.300 |
| neutral | glycine, -H | nonpolar | Gly |
| Body_ID: T002002.350 |
| | amides, -CONH2 | polar | Asn, Gln |
| Body_ID: T002002.400 |
| | hydroxyl, -OH | polar | Ser, Thr, |
| Body_ID: T002002.450 |
| | sulfhydryl, -SH | nonpolar | Cys |
| Body_ID: T002002.500 |
| aliphatic | hydrocarbon | nonpolar | Ala, Val, Leu, |
| Body_ID: T002002.550 |
| | | | Ile, Met, Pro |
| Body_ID: T002002.600 |
| aromatic | C-rings | nonpolar | Phe, Trp, Tyr |
| Body_ID: T002002.650 |
| Table 2.2 depicts the functional groups of amino acids and their polarity (hydrophilicity). Polar side chains can be
involved in hydrogen bonding to water and to other polar groups. The hydrophobic nature of side chains contributes to protein folding by hydrophobic interactions.
|
|
