Why must integral proteins be amphipathic?

Integral proteins must be amphipathic because they need to interact with both the hydrophobic interior of the lipid bilayer and the hydrophilic environment on either side of the membrane. Being amphipathic means that these proteins contain both hydrophilic (water-attracting) and hydrophobic (water-repelling) regions. This characteristic enables them to embed themselves within the membrane while still interacting appropriately with the aqueous environments outside and inside the cell.

This structural feature is crucial for their function, allowing integral proteins to play roles such as transporting molecules across the membrane, participating in signaling pathways, or acting as receptors. Without the amphipathic nature, these proteins would not be able to effectively anchor within the lipid bilayer, which would limit their proper functionality in cellular processes.