Define Uniport, Symport and Antiport. Do they require energy? I) Uniport: When a single substance moves in a single direction across a cell membrane, it is called uniport. II) Antiport: When two substances move in the opposite direction across a cell membrane, it is called antiport. III) Symport: When two substances move in the same direction across a cell membrane, it is called symport.

Question

Philoid · Accepted Answer

Uniport, Symport and antiport are kind of facilitated diffusion where the diffusion is facilitated by carrier proteins and channel proteins along a concentration gradient so energy is not required directly. Symporters and antiporters though are also involved in active transport where they require energy.