What process involves the removal of one sulfur atom and its replacement with a disulfide bond?

The process that involves the removal of one sulfur atom and its replacement with a disulfide bond is lanthionization. This technique is commonly used in permanent waving and chemical texture services. During lanthionization, the original disulfide bonds in the hair, which are responsible for its natural curl and wave pattern, are altered. Specifically, one sulfur atom from a disulfide bond is removed, resulting in a new bond called a lanthionine bond. This modification leads to a change in the internal structure of the hair, allowing for different styling options and improved control over the curl pattern.

This process is distinct from oxidation, reduction, and hydrolysis. Oxidation generally involves the addition of oxygen to a compound while reducing its electron count, which does not specifically pertain to the removal of sulfur atoms. Reduction, on the other hand, refers to the gain of electrons or the addition of hydrogen, neither of which defines the lanthionization process. Hydrolysis involves the chemical breakdown of a compound due to a reaction with water, which also does not relate directly to sulfur atom manipulation. Thus, lanthionization specifically describes the unique process where sulfur atoms are manipulated to create new structural bonds within the hair.