Question

the structure on the right in the figure below forms a part of many proteins. it is also part of a molecule that is one of the most common chemical signals in your brain. it is the ionized form of the structure on the left. this ionization occurs when the molecule on the left is placed in water. (note that when scientists draw molecules like this, they often leave out some of the dashes representing covalent bonds, and just write oh or ch3 to make the diagrams less cluttered and easier to read.) which of the following statements are true? select all that apply. the structure on the left will not dissolve in water, due to the nonpolar ch3 groups. the structure on the left will dissolve in water, due to the polar oh and c = o groups. the structure on the right carries a full charge from the c - o group and a partial charge from the c = o group. the structure on the left is an acid. the structure on the right carries a partial charge on the c - o group and a full charge on the c = o group.

Explanation:

1. The left - hand structure has polar OH and C=O groups which can form hydrogen bonds with water, so it will dissolve in water, making the first statement false and the second true.
2. The structure on the right has a full negative charge on the C - O group (it is an anion) and the C=O group has a partial charge due to electronegativity differences, but the description in the third statement is incorrect.
3. The structure on the left has a carboxyl group ( - COOH), which is an acid, so the fourth statement is true.
4. The charge description in the fifth statement is incorrect. The full charge is on the C - O group and partial on C=O.

Answer:

B. The structure on the left will dissolve in water, due to the polar OH and C = O groups.
D. The structure on the left is an acid.