Which of the following molecules forns the binding site of ribosome on RER?

Options

A. Lipoprotein
B. Lipopolysaccharide
C. Glycoprotein
D. Phosphoprotein

Answer

To solve the question regarding which molecule forms the binding site of ribosomes on the Rough Endoplasmic Reticulum (RER), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of RER**: The Rough Endoplasmic Reticulum (RER) is characterized by the presence of ribosomes on its cytoplasmic surface, which gives it a "rough" appearance. These ribosomes are essential for protein synthesis.

2. **Identify the Role of Ribosomes**: Ribosomes are the molecular machines that translate messenger RNA (mRNA) into proteins. They bind to the RER to synthesize proteins that are either secreted from the cell, incorporated into the cell's plasma membrane, or sent to an organelle.

3. **Consider the Binding Molecules**: The question asks which molecules form the binding site for ribosomes on the RER. The binding site typically consists of specific proteins or molecules that facilitate the attachment of ribosomes to the RER.

4. **Evaluate the Options**: The options provided in the question include:
- Lipoprotein
- Lipopolysaccharide
- Glycoprotein
- Phosphoprotein

5. **Analyze Each Option**:
- **Lipoprotein**: This is a complex of lipids and proteins, but it does not specifically form the binding site for ribosomes.
- **Lipopolysaccharide**: This is a large molecule composed of a lipid and a polysaccharide, primarily found in the outer membrane of Gram-negative bacteria, not related to ribosome binding.
- **Glycoprotein**: Glycoproteins are proteins that have carbohydrate groups attached to them. They are often found on the cell surface and play a role in cell recognition and signaling. They can serve as binding sites for ribosomes on the RER.
- **Phosphoprotein**: These are proteins that have phosphate groups attached. They are involved in various cellular processes but do not specifically serve as binding sites for ribosomes on the RER.

6. **Select the Correct Answer**: Based on the analysis, the correct answer is **Glycoprotein**, as it serves as the binding site for ribosomes on the Rough Endoplasmic Reticulum.

### Final Answer:
The molecule that forms the binding site of ribosomes on the Rough Endoplasmic Reticulum (RER) is **Glycoprotein**.