Advanced Placement (AP) Biology Practice Exam

Which property allows carbon to form various organic compounds?

1. It possesses a positive charge

2. It can form stable covalent bonds

3. It is nonpolar

4. It can only form two bonds

The correct answer is: It can form stable covalent bonds

Carbon's ability to form various organic compounds is primarily due to its capacity to create stable covalent bonds. Carbon has four valence electrons, allowing it to form four covalent bonds with other atoms. This tetravalency enables carbon to connect with a wide range of elements, including itself. The stability of these covalent bonds is critical for the formation of complex molecules like carbohydrates, proteins, lipids, and nucleic acids, which are essential biological macromolecules. Through these stable covalent bonds, carbon can create long chains, branched structures, and even rings, leading to an enormous diversity of organic compounds. This versatility is fundamental to the complexity of organic chemistry and the biochemical processes of living organisms.