Carbon typically forms covalent bonds to create biomolecules. Specifically, carbon atoms can form up to four covalent bonds with other atoms, including other carbon atoms, hydrogen, oxygen, nitrogen, and more. These bonds can be single, double, or triple covalent bonds:
- Single bonds involve sharing one pair of electrons and are the most common in biomolecules, such as in alkanes (e.g., methane) and in carbon-hydrogen bonds in organic molecules.
- Double bonds involve sharing two pairs of electrons, as seen in alkenes and in some functional groups in biomolecules. They affect molecular geometry and reactivity.
- Triple bonds involve sharing three pairs of electrons and are less common but important in some biological molecules.
Carbon's ability to form these different types of covalent bonds allows it to create complex structures such as long chains, branched chains, and rings, which form the backbone of biomolecules like carbohydrates, proteins, lipids, and nucleic acids. This versatility also enables the formation of isomers, molecules with the same formula but different structures, contributing to the diversity of biological molecules. In addition to carbon-carbon bonds, carbon forms covalent bonds with other atoms (e.g., C-H, C-O, C-N) to build the complex macromolecules essential for life. These covalent bonds are strong and stable, enabling the formation of large, complex, and functional biological molecules
