In active transport

Options

A. Energy is required
B. Membrane porteins are involved
C. Pumps are present
D. All of these

Answer

**Step-by-Step Solution:**

1. **Understanding Active Transport**: Active transport is a process where substances move across a cell membrane against their concentration gradient, meaning from an area of lower concentration to an area of higher concentration. This process requires energy.

2. **Energy Requirement**: In active transport, energy is required to move molecules against their concentration gradient. This energy is usually derived from ATP (adenosine triphosphate).

3. **Role of Membrane Proteins**: Active transport involves specific membrane proteins known as transporter proteins or pumps. These proteins facilitate the movement of substances across the membrane.

4. **Presence of Pumps**: Pumps are specialized proteins that actively transport ions or molecules across the membrane. They are essential for maintaining concentration gradients across the cell membrane.

5. **Conclusion**: Given that energy is required, membrane proteins are involved, and pumps are present in active transport, the correct answer to the question is "all of the above".

**Final Answer**: All of the above.

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