Distinguish between channel proteins and carrier proteins

A channel protein is a special arrangement of amino acids which embeds in the cell membrane, providing a hydrophilic passageway for water and small, polar ions. Like all transport proteins, each channel protein has a size and shape which excludes all but the most specific molecules.

Carrier proteins are proteins that carry substances from one side of a biological membrane to the other. ... However, carrier proteins can also be used for facilitated diffusion, a form of passive transport. Carrier proteins typically have a “binding site” which will only bind to the substance they're supposed to carry.

oxygen = 21% of the atmosphere

nitrogen = 78%

carbon dioxide = 0.1%

argon =0.934%