Q25 of 67 Page 58

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.


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.


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