Channel proteins are specialized proteins embedded in cell membranes that facilitate the movement of ions and molecules across the membrane. They form pores that allow specific substances, such as sodium ions or potassium ions, to pass through, helping maintain the cell's internal environment. These proteins are crucial for various cellular processes, including nerve signal transmission and muscle contraction. Unlike carrier proteins, which change shape to transport substances, channel proteins provide a direct pathway for molecules to flow in and out of the cell. They can be gated, meaning they open or close in response to specific signals, ensuring that the cell can regulate its internal conditions effectively.