Specific proteins responsible for the flow of materials and information into the cell are called

Options

A. membrane receptors
B. carrier proteins
C. integral proteins
D. none of these

Explanation

### Step-by-Step Solution

1. **Understanding the Question**: The question asks about specific proteins that facilitate the flow of materials and information into the cell.

2. **Identifying the Options**: The options provided are:
- A) Membrane receptors
- B) Carrier proteins
- C) Integral proteins
- D) None of these

3. **Analyzing Each Option**:
- **Membrane Receptors**: These proteins bind to specific molecules (ligands) and transmit signals into the cell but do not directly transport materials.
- **Carrier Proteins**: These proteins are responsible for the transport of substances across the cell membrane. They can facilitate both active transport and facilitated diffusion, which involves conformational changes to move materials into the cell.
- **Integral Proteins**: These are embedded within the membrane and can serve various functions, but they are not specifically responsible for the flow of materials and information.
- **None of These**: This option suggests that none of the previous options are correct.

4. **Choosing the Correct Answer**: Based on the analysis, the correct answer is **B) Carrier proteins**. These proteins are specifically responsible for the flow of materials and information into the cell, especially during active transport where energy is required.

5. **Conclusion**: The specific proteins responsible for the flow of materials and information into the cell are called **carrier proteins**.