SER Full Form

SER is tubular endoplasmic reticulum without ribosomes. It’s found in eukaryotic cells and has a role in lipid synthesis, carbohydrate metabolism, calcium concentration control and drug detoxification. The ER is one of a eukaryotic cell’s most apparent organelles. The endoplasmic reticulum comprises cisternae, which are linked networks of flattened sacs. The ER membranes are attached to the outer nuclear envelope and can potentially extend into the cell membrane. Many metabolic activities rely on the SER. For example, it produces lipids, phospholipids and steroids found in plasma membranes. As a result, the smooth endoplasmic reticulum is overproduced in cells that emit these compounds, such as testes, ovaries and skin oil glands.

What is the full form of SER?

SER full form is the smooth endoplasmic reticulum. The smooth endoplasmic reticulum is a meshwork of tiny disklike tubular membrane vesicles in the cytoplasm of eukaryotic cells involved in synthesising and storing lipids like cholesterol and phospholipids are employed in the formation of new cellular membranes.

The lack of ribosomes distinguishes the smooth endoplasmic reticulum (SER) from the rough endoplasmic reticulum (RER), the second leading form of the endoplasmic reticulum. Ribosomes are protein-synthesising particles connected to the RER’s outer surface to give the membrane its “rough” look. SER is found in both animal and plant cells.

Discovery of SER

Despite Being one of the most prominent and functionally significant organelles, the endoplasmic reticulum was identified late. ER was first detected using light microscopy in 1902 by French cytologist Charles Garnier and colleagues. Their observations, however, were not widely accepted by their contemporaries. As a result, the world had to wait another 50 years for two scientists to verify the presence of the endoplasmic reticulum, thanks to the invention of electron microscopy. Finally, Keith R. Porter and George E. Palade, two American cell scientists, discovered a net-like (reticulum) structure within (endo) the cytoplasm (plastic) in 1953 and termed the organelle “endoplasmic reticulum.” The structure, content and role of the endoplasmic reticulum in muscle contraction and calcium control had been defined by the early 1960s. Günter Blobel discovered that the ER was involved in protein production in 1971.

Structure of the SER

The smooth endoplasmic reticulum, unlike the rough endoplasmic reticulum, does not have ribosomes on its surface, therefore the name. Instead the nuclear envelope is related to smooth ER, extending throughout the cytoplasm. It comprises a membrane-enclosed network of tubules and vesicles arranged in a reticular pattern to provide more surface area for the action or storage of key enzymes.

The tubules in the SER are more variable in diameter than those in the rER, and they branch and join among themselves more often, forming a compact three-dimensional reticulum. SER can also take the shape of concentric or spiral arrays of strongly fenestrated cisternae in steroid-secreting cells. The lumen, surrounded by a phospholipid membrane, is inside the smooth endoplasmic reticulum.

Location of SER

Almost all eukaryotic cells have a smooth endoplasmic reticulum. Some eukaryotic cells, such as eggs, embryonic cells and adult RBCs, do not have SER. Some specialised cells, on the other hand, are high in SER. Sebaceous glands, gonadal cells that produce steroid hormones, hepatocytes in the liver and striated muscle cells are examples of cells with abundant SER.

Functions

The SER is essential for cellular metabolism. The many metabolic processes in which SER is involved differ by cell type and they are numerous in cell types that rely primarily on SER activities. Lipid synthesis, glucose metabolism, intracellular calcium concentration modulation and drug detoxification are all significant activities of the SER. The SER comprises a diverse set of enzymes involved in the production of lipids, including phospholipids and steroids. SER is abundant in cells producing these products, such as those found in the testes, ovaries and skin oil glands. SER is also essential for cholesterol homeostasis. Even though the endoplasmic reticulum produces very little cholesterol, it houses most molecular machinery that controls cellular cholesterol homeostasis. The smooth endoplasmic reticulum also helps chemicals synthesised in the rough ER get to the Golgi complex.

Conclusion

Both eukaryotic animal and plant cells have an endoplasmic reticulum organelle. Rough ER and smooth ER are two interrelated sub-compartments that emerge often. Both kinds are made up of flattened tubes joined by a membrane. The rough ER is involved in manufacturing, folding, quality checking, and dispatching specific proteins with millions of membrane-bound ribosomes. In contrast, Smooth ER is closely linked to lipid (fat) synthesis, metabolism, and steroid hormone production. It also has a detoxifying effect. SER is also necessary for maintaining cholesterol homeostasis.