Which cellular structures are included in endomembrane system?

Answer

### Step-by-Step Solution:

1. **Understanding the Endomembrane System**: The endomembrane system is a collection of membranes that are involved in the synthesis, modification, and transport of proteins and lipids within the cell. It plays a crucial role in the overall functioning of the cell.

2. **Identifying Key Structures**: The major cellular structures that are part of the endomembrane system include:
- **Endoplasmic Reticulum (ER)**: This is divided into two types:
- **Rough Endoplasmic Reticulum (RER)**: Studded with ribosomes, it is involved in protein synthesis.
- **Smooth Endoplasmic Reticulum (SER)**: Lacks ribosomes and is involved in lipid synthesis and detoxification processes.
- **Golgi Apparatus**: This structure modifies, sorts, and packages proteins and lipids for secretion or for use within the cell.
- **Lysosomes**: These are membrane-bound organelles that contain digestive enzymes to break down waste materials and cellular debris.

3. **Function of the Endomembrane System**: The endomembrane system is essential for the synthesis of various compounds required by the cell. It facilitates the formation of secretory vesicles that transport these compounds to their destinations.

4. **Summary of Structures**: To summarize, the cellular structures included in the endomembrane system are:
- Endoplasmic Reticulum (both Rough and Smooth)
- Golgi Apparatus
- Lysosomes