transporters

Transporters is a broad term used for systems and proteins that move substances or energy from one location to another. The word appears in biology, where transporter proteins move molecules across cell membranes; in science fiction, where “transporters” teleport matter; and in engineering and logistics, where systems are described as moving people and goods.

Biological transporters are commonly classified as channels, carriers (or porters), and pumps. Channels provide aqueous pores that allow ions or water to pass by facilitated diffusion. Carriers bind substrates and undergo conformational changes to shuttle them across membranes. Pumps use energy, typically ATP, to move substances against their gradients. Examples include aquaporins, GLUT transporters, and the Na+/K+-ATPase.

Transporter function influences pharmacology and physiology. In humans, transporter proteins affect absorption, distribution, and excretion of drugs. Inhibition or genetic variation can alter drug responses and contribute to resistance. P-glycoprotein (ABCB1) and other ABC transporters are well-studied in cancer and infectious diseases.

In popular culture, transporters are fictional devices that dematerialize and rematerialize subjects at a distance, most famously in Star Trek. They are not known to operate under real-world physical laws as currently understood.

See also: transporter proteins, channel proteins, active transport, diffusion.