What does the sulfhydryl functional group consist of?

The sulfhydryl functional group consists of a sulfur atom bonded to a carbon atom and a hydrogen atom, which is accurately represented by the chosen answer. This functional group is important in biological molecules, particularly in the structure of proteins, where it can form disulfide bonds. These bonds contribute to the stability and three-dimensional structure of proteins, playing a crucial role in their function. The presence of the -SH group in cysteine, for example, allows for the formation of these important linkages. The versatility of the sulfhydryl group is significant in biochemical reactions, further demonstrating its importance in living organisms.