‘Uniporter’ is involved in the transport of

Options

A. Two molecules move together in the same direction
B. Two molecules move together in opposite direction
C. More than two molecules move either same or in opposite directions
D. Single molecule moves across the membrane in one direction only

Answer

**Step-by-Step Solution:**

1. **Understanding Uniporter**: A uniporter is a type of transport protein that facilitates the movement of substances across a cell membrane. It is specific to a single type of molecule.

2. **Function of Uniporter**: Uniporters operate by allowing one molecule to bind to the transport protein and then move across the membrane. This process is known as facilitated diffusion.

3. **Direction of Transport**: The key characteristic of a uniporter is that it transports only one type of molecule at a time, and it moves this molecule in one direction across the membrane.

4. **Identifying the Correct Option**: Given the options:
- Option 1: Two molecules move together in the same direction (this describes a symporter).
- Option 2: Molecules move together in opposite directions (this describes an antiporter).
- Option 3: More than two molecules move either in the same or opposite directions (this does not apply to uniporters).
- Option 4: A single molecule moves across the membrane in one direction (this accurately describes the function of a uniporter).

5. **Conclusion**: The correct answer is option number four: "single molecule moves across the membrane in one direction."

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