Draw two amino acids – note the amino group, the carboxyl group and the alpha carbon, circle the water molecule to be removed and then note the peptide bond formed when the two are joined.

The two Amino Acids drawn are;

                        1) Proline  (Red)

                         2) Histidine (Blue)

The Carboxylic Groups are encircled in Yellow Sphere.

The Amino Groups are encircled in Orange Spheres.

The Alpha carbons are encircled in Pink spheres.

The water molecule evolved is in corresponding colors of its parent molecules.

The peptide bond formed is colored by Green color.

1. a)c-14 has two more protons

2. d)they have different numbers of protons, neutrons, and valence electrons; they are all gases at room temperature.

3. c) iron and nickel.