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.