‘Pump’ proteins in active transport:

Options

A. Are present in cell wal
B. Perform downhill transport
C. Do not use energy
D. Perform uphill transport

Answer

**Step-by-Step Solution:**

1. **Understanding Pump Proteins:**
- Pump proteins are specialized membrane proteins that facilitate the movement of ions or molecules across a cell membrane.

2. **Location of Pump Proteins:**
- Pump proteins are not located in the cell wall; they are embedded in the plasma membrane of cells.

3. **Energy Requirement:**
- Pump proteins require energy to function. This energy is typically derived from ATP (adenosine triphosphate).

4. **Direction of Transport:**
- Pump proteins are involved in active transport, which means they move substances against their concentration gradient. This is referred to as "uphill transport," where substances move from an area of lower concentration to an area of higher concentration.

5. **Conclusion:**
- Based on the above points, the correct statement regarding pump proteins in active transport is that they perform "uphill transport."

**Final Answer:**
- Pump proteins in active transport perform uphill transport.

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