Sulfur-based compounds are chemical substances that contain sulfur as a key element. These compounds can be found in various forms, such as gases, liquids, or solids, and are often used in industrial processes. Common examples include sulfur dioxide, which is used in the production of sulfuric acid, and sulfates, which are found in fertilizers. In nature, sulfur-based compounds play essential roles in biological systems. For instance, amino acids like cysteine and methionine contain sulfur and are vital for protein synthesis. Additionally, sulfur is a crucial element in the sulfur cycle, which helps maintain ecological balance by recycling sulfur through the environment.