These structures are enclosed by a single membrane, which separates the ER lumen from the cytoplasm of the cell. The endoplasmic reticulum is composed of a network of interconnected tubules and flattened sacs called cisternae. Additionally, the SER plays a role in the detoxification of drugs and other harmful substances by enzymatic reactions. It is responsible for the synthesis of lipids, including phospholipids and steroids. On the other hand, the SER is involved in lipid metabolism and detoxification processes. The RER also plays a crucial role in protein quality control, ensuring that misfolded proteins are properly identified and either refolded or degraded. The ribosomes attached to the RER synthesize proteins that are destined for secretion or incorporation into the cell membrane. It is involved in the biogenesis of organelles and the production of secretory proteins. The RER is primarily responsible for protein synthesis and folding. The RER is studded with ribosomes on its surface, giving it a rough appearance, while the SER lacks ribosomes and appears smooth. The distinction between these two types is based on their appearance and function. The ER can be categorized into two main types: the rough endoplasmic reticulum (RER) and the smooth endoplasmic reticulum (SER). The ER is a complex network of membranous tubules and sacs that extends throughout the cytoplasm of the cell. It plays a crucial role in various cellular processes, including protein synthesis, lipid metabolism, calcium storage, and detoxification processes. The endoplasmic reticulum (ER) is a vital organelle found in eukaryotic cells. Image by Laboratoires Servier – Wikimedia Commons, Wikimedia Commons, Licensed under CC BY-SA 3.0. Definition and Structure of Endoplasmic Reticulum Image by Laboratoires Servier – Wikimedia Commons, Wikimedia Commons, Licensed under CC BY-SA 3.0. Intracellular transport The ER provides a network of membranes for the transport of molecules within the cell. Detoxification The smooth ER is involved in the detoxification of drugs, alcohol, and other harmful substances. Calcium storage The ER acts as a calcium reservoir, regulating calcium levels in the cytoplasm and playing a role in cell signaling. Lipid metabolism The smooth ER is responsible for the synthesis of lipids, including phospholipids and steroids.

Key Takeaways Function Description Protein synthesis The rough ER is involved in the synthesis of proteins, including membrane proteins and secretory proteins. Overall, the endoplasmic reticulum is a multifunctional organelle that is essential for the proper functioning of cells. The ER also serves as a transportation system, allowing molecules to move between different parts of the cell. It can be divided into two regions: the rough ER, which is studded with ribosomes and involved in protein synthesis, and the smooth ER, which lacks ribosomes and is responsible for lipid metabolism and detoxification. The ER consists of a network of membranous tubules and sacs that extend throughout the cytoplasm. It plays a crucial role in various cellular functions, including protein synthesis, lipid metabolism, and calcium storage.

Er lumen protein