A channel protein serves as a tunnel across the membrane into the cell. More specifically, channel proteins help molecules across the membrane via passive transport, a process called facilitated diffusion. These channel proteins are responsible for bringing in ions and other small molecules into the cell
Boiling point. If you boil water it changes from a liquid to a gas, which is a physical change. The rest are chemical properties because the chemical make up of an object changes.
The lacrimal<span> glands secrete tears which act to lubricate and protect the cornea and eyeball from injury which may result from small particles such as dust. Tears are a watery fluid with an electrolyte content similar to that of plasma and contains: bactericidal enzymes known as lysozyme and lactoferrin.</span>