1. Ribosomes: These are the sites of protein synthesis. They translate the genetic code from mRNA into a polypeptide chain (protein).
2. Endoplasmic Reticulum (ER): The ER is a network of interconnected membranes where proteins are folded and modified.
* Rough ER: Studded with ribosomes, responsible for protein synthesis and initial folding.
* Smooth ER: Involved in lipid synthesis, detoxification, and calcium storage.
3. Golgi Apparatus: This organelle further modifies, sorts, and packages proteins into vesicles. It acts like a processing and distribution center.
4. Transport Vesicles: Small membrane-bound sacs that bud off from the Golgi and carry proteins to their final destination.
5. Plasma Membrane: The outer boundary of the cell. Transport vesicles fuse with the plasma membrane, releasing their contents outside the cell through a process called exocytosis.
In summary:
* Ribosomes synthesize proteins.
* ER folds and modifies proteins.
* Golgi further processes and packages proteins.
* Vesicles transport proteins.
* Plasma membrane releases proteins outside the cell.