Final answer:
A symporter transports two different molecules or ions in the same direction, an antiporter transports two different molecules or ions in opposite directions, and a uniporter transports only one specific molecule or ion.
Step-by-step explanation:
A symporter is a type of carrier protein that transports two different molecules or ions in the same direction. An example of a symporter is the sodium-glucose symporter, which uses sodium ions to transport glucose molecules into the cell against its concentration gradient.
An antiporter, on the other hand, is a carrier protein that transports two different molecules or ions in opposite directions. An example of an antiporter is the sodium-hydrogen ion antiporter, which uses the energy from the inward flood of sodium ions to move hydrogen ions out of the cell.
A uniporter is a carrier protein that transports only one specific molecule or ion. An example of a uniporter is the glucose transporter, which transports glucose molecules across the cell membrane.