Glycoproteins are molecules made up of proteins and carbohydrates. They play essential roles in various biological processes, such as cell recognition, signaling, and immune responses. The carbohydrate part, or sugar chain, is attached to the protein, which helps the glycoprotein perform its specific functions in the body. These molecules are found on the surface of cells and in bodily fluids, contributing to the structure and function of tissues. For example, glycoproteins are crucial in the immune system, helping antibodies recognize and bind to pathogens like bacteria and viruses. Their diverse roles make them vital for maintaining health and supporting various cellular activities.