Integral proteins are a type of membrane protein that are embedded within the lipid bilayer of cell membranes. They play crucial roles in various cellular functions, including transport, communication, and maintaining the structure of the cell. These proteins can span the entire membrane, which allows them to interact with both the internal and external environments of the cell. Due to their position in the membrane, integral proteins can act as channels or carriers for molecules, facilitating the movement of substances like ions and nutrients. They are also involved in signaling pathways, helping cells respond to external signals. Examples of integral proteins include ion channels and receptors.