Covalent bonds form through the sharing of at least 2 electrons. Carbon based rings & chains form very large molecules because carbon can form up to 4 covalent bonds to form these rings and chains, and these bond with other rings and chains over and over. Glucose→Starches. Lipids, proteins, carbohydrates, and nucleic acids are the 4 main types of carbon-based molecules in organisms. Nucleic acids form our genetic code. Genetic information is stored in those. Proteins are also made from nucleic acids.