retikulummembran
Retikulummembran refers to the network of membranes that make up the endoplasmic reticulum in eukaryotic cells. This extensive intracellular structure is composed of flattened sacs and tubules called cisternae, all enclosed by a lipid bilayer membrane continuous with the outer nuclear membrane. The retikulummembran encloses a lumen, or internal space, known as the cisternal space, which is distinct from the cytoplasm. The structure and composition of the retikulummembran vary slightly between the rough endoplasmic reticulum and the smooth endoplasmic reticulum. The rough endoplasmic reticulum is studded with ribosomes on its cytoplasmic surface, which are responsible for protein synthesis and modification, while the smooth endoplasmic reticulum lacks ribosomes and is involved in lipid synthesis, detoxification, and calcium storage. The retikulummembran plays a crucial role in protein folding, quality control, and transport, as well as lipid metabolism and calcium homeostasis, all essential for cellular function and survival. Its dynamic nature allows it to expand and contract, adapting to the cell's metabolic needs.