3. Amino Acids

Fill-in the missing R-groups for the following peptide from memory: D-I-F-C-R-Q.

Which of the 20 standard amino acids can be grouped into the following categories?

a. Contain cyclic/ring structures.                                                     b. Sulfur-containing.

Fill-in the blanks & R-groups for each of the α-amino acids from memory.

Match the amino acid to the type of R-group it has:

Leu ____                                   1. Hydroxyl-containing

E ____                                      2. Acidic

K ____                                      3. Basic

Ser ____                                  4. Sulfur-containing

C ____                                     5. Nonpolar aromatic

W ____                                    6. Nonpolar aliphatic

Name the amino acids that contain each of the following in their R-groups:

a) Hydroxyl group: __________________                      e) Sulfur atom: ­­­­­­­__________________

b) 2^nd chiral carbon: __________________                    f) Amino group: __________________

c) Amide group: __________________                          g) Acidic group: __________________

d) Basic group: __________________                           h) Aromatic ring: __________________