NANP Board Practice Exam

Unsaturated fatty acids are characterized by the presence of what?

1. Carboxyl groups

2. Double bonds between carbon atoms

3. Methyl groups

4. No double bonds between carbon atoms

The correct answer is: Double bonds between carbon atoms

Unsaturated fatty acids are known for having double bonds between their carbon atoms. These bonds are what characterize unsaturated fatty acids and make them different from saturated fatty acids. Option A, carboxyl groups, are present in both saturated and unsaturated fatty acids, so this cannot be the correct answer. Option C, methyl groups, are also present in both types of fatty acids, so this is not the correct answer either. Option D, no double bonds between carbon atoms, is in fact the opposite of what characterizes unsaturated fatty acids, making it an incorrect answer. Therefore, the correct answer is B, double bonds between carbon atoms.