What do channel proteins provide for specific molecules or ions to cross the membrane?

Channel proteins serve as specialized pathways that facilitate the passage of specific molecules or ions across cell membranes. These proteins create hydrophilic channels that allow certain substances, which may be too polar or charged to pass through the lipid bilayer directly, to move in and out of the cell more easily.

The term 'corridors' aptly describes the function of channel proteins, as they provide designated routes through the membrane. This enables the selective transport of ions such as sodium, potassium, calcium, or chloride, and larger molecules, while regulating the flow and maintaining homeostasis within the cell.

Choosing 'corridors' highlights the structural role that these proteins play in forming a specific passageway through which substances can travel, distinguishing them from barriers that would block movement or from other transport mechanisms that might involve more complex processes. Additionally, while 'pores' could be a close alternative, 'corridors' emphasizes the guided and selective nature of channel proteins.