The term "-COO⁻" refers to the carboxylate ion, which is the deprotonated form of a carboxylic acid. In this structure, the carboxyl group (-COOH) loses a hydrogen ion (H⁺), resulting in a negatively charged ion. Carboxylate ions are commonly found in various organic compounds and play a significant role in biochemical processes. Carboxylate ions are important in the formation of salts and esters. They can interact with positively charged ions, such as Na⁺ or K⁺, to form carboxylate salts. Additionally, they are involved in metabolic pathways, including the citric acid cycle, where they contribute to energy production in living organisms.