Carrier-mediated transport

Carrier-mediated transport is a fundamental biological mechanism describing the movement of solutes across cellular membranes through specific, integral membrane proteins known as transporters or carriers (StatPearls, 2023). This process is distinct from simple diffusion as it is substrate-specific, saturable, and subject to competitive inhibition (NIH, 2022). It includes facilitated diffusion, which occurs down a concentration gradient, and active transport, which utilizes energy to move molecules against a gradient (Wikipedia, 2024). Transporters facilitate the uptake of essential nutrients like glucose and amino acids, the maintenance of ion gradients, and the efflux of metabolic wastes and xenobiotics (PubMed, 2021). In pharmaceutical science, carrier-mediated transport is a key factor in drug pharmacokinetics, determining the absorption, distribution, and excretion profiles of various therapeutic agents (Nature Reviews Drug Discovery, 2010). Although the term refers to a general physiological process rather than a specific molecular entity, individual proteins within the Solute Carrier (SLC) and ATP-Binding Cassette (ABC) families are critical targets for drug development across multiple therapeutic areas.

Other names

Facilitated diffusionActive transportProtein-mediated transportCarrier-mediated diffusionTransporter-mediated transport

Movement of substances across biological membranes via substrate-specific carrier proteins that undergo conformational changes to facilitate translocation.