The primary elements that make up organic compounds are carbon (C), hydrogen (H), oxygen (O), nitrogen (N), phosphorus (P), and sulfur (S). These elements are vital for forming the building blocks of life, including proteins, carbohydrates, lipids, and nucleic acids. Carbon, in particular, serves as the backbone for complex organic structures due to its ability to form bonds with many other atoms. The unique properties of these elements and their compounds enable the vast diversity of biological functions and structures necessary for sustaining life.