Disulfides are chemical compounds that contain a bond between two sulfur atoms. This bond is represented as -S-S- and is commonly found in various organic molecules, including proteins. In proteins, disulfide bonds help maintain their three-dimensional structure, contributing to their stability and function. Disulfides can be formed through a reaction between two thiol groups, which are functional groups containing sulfur and hydrogen. These compounds are important in biochemistry and are often involved in the formation of keratin, a key structural protein in hair and nails, as well as in the stabilization of enzymes.