Which molecules in the plasma membrane provide cell identity?

Cell identity is primarily provided by glycoproteins and glycolipids in the plasma membrane. These molecules have carbohydrate chains that extend from their surfaces, forming unique markers that can be recognized by other cells and the immune system. This recognition is crucial for processes such as cell communication, tissue formation, and immune responses. Additionally, these markers help distinguish between self and non-self cells, playing a key role in immune function.