Final answer:
An amphipathic protein has both hydrophilic and hydrophobic regions, allowing it to integrate into the cell membrane and perform functions such as transport or signal transduction.
Step-by-step explanation:
An amphipathic protein is a type of protein that has regions that are both hydrophilic (water-loving) and hydrophobic (water-hating). This feature allows the protein to insert into a cell membrane, which is composed of a lipid bilayer with a hydrophobic interior and hydrophilic exterior. Integral membrane proteins, which are amphipathic, have hydrophobic domains that non-covalently interact with the fatty acid interior of membranes, and hydrophilic domains that interact with the aqueous environments on either side of the membrane.
These integral proteins often span the entire membrane, with hydrophilic domains facing the cell's exterior and interior environments and hydrophobic domains embedded within the lipid bilayer. This arrangement is crucial for proteins' functions, such as forming channels or pores that enable the transport of ions and polar molecules across the otherwise impermeable membrane, or serving as receptors that transmit signals into the cell.