Ribosomes are attached to endoplasmic reticulum through

Options

A. Ribophorins
B. r-RNA
C. t-RNA
D. Hydrophobic interaction

Answer

To answer the question "Ribosomes are attached to endoplasmic reticulum through," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Ribosomes and Endoplasmic Reticulum (ER)**:
- Ribosomes are cellular structures responsible for protein synthesis.
- The endoplasmic reticulum (ER) is an organelle involved in the synthesis of proteins and lipids. There are two types of ER: rough ER (RER) and smooth ER (SER). The rough ER has ribosomes attached to its surface.

2. **Identifying the Connection**:
- Ribosomes attach to the rough endoplasmic reticulum (RER) to facilitate the translation of mRNA into proteins directly into the lumen of the ER.

3. **Exploring the Options**:
- The options provided are:
1. Riboflavin
2. Ribosomal RNA
3. Transfer RNA
4. Hydrophobic interaction
- We need to determine which of these options correctly describes how ribosomes are attached to the ER.

4. **Analyzing the Correct Option**:
- Ribosomes are not attached to the ER through riboflavin, ribosomal RNA, or transfer RNA. Instead, they attach through a mechanism involving proteins, specifically glycoproteins that help in anchoring the ribosomes to the ER.

5. **Conclusion**:
- The ribosomes are attached to the endoplasmic reticulum through glycoproteins, which are not listed in the options. However, based on the context provided in the video transcript, the closest answer given is riboflavin, which is incorrect in a strict biological sense but was mentioned in the context of the discussion.

### Final Answer:
Ribosomes are attached to the endoplasmic reticulum through glycoproteins.