Endoplasmic reticulum diagram 2d. In endoplasmic reticulum smooth er by contrast is not associated with ribosomes and its functions differ. The endoplasmic reticulum is part of the endomembrane system which refers to the group of organelles whose responsibility is to create package modify and transport proteins and lipids around the cell and outside of the cell. The sarcoplasmic reticulum is a specialized type of smooth er that regulates the calcium ion concentration in the cytoplasm of striated muscle cells. Some cisternae of er have a granular appearance in electron micrographs.
Structure of endoplasmic reticulum with diagram botany. Such an endoplasmic reticulum is called granular or rough endoplasmic reticulum. The endoplasmic reticulum er is a dynamic organelle responsible for many cellular functions including the synthesis of proteins and lipids and regulation of intracellular calcium levels. In cells of the liver it contributes to the detoxification of drugs and harmful chemicals.
Consisting of tubules sheets and the nuclear envelope. The membrane of the rough endoplasmic reticulum forms large double membrane sheets that are located near and continuous with the outer layer of the nuclear envelope. The smooth er is involved in the synthesis of lipids including cholesterol and phospholipids which are used in the production of new cellular membrane. The double membrane sheets are stacked and connected through several right or left handed helical ramps the so called terasaki ramps.
The endoplasmic reticulum is only one. The entire structure can account for a large proportion of the endomembrane system of the cell. The rough endoplasmic reticulum manufactures membranes. This review focuses on the distinct and complex morphology of the er.
The smooth er has a wide range of functions including carbohydrate. In certain cell types smooth er plays an. The endoplasmic reticulum er is a large dynamic structure that serves many roles in the cell including calcium storage protein synthesis and lipid metabolism. The membranes appear to be continuous with the plasma membrane at the outer surface and with the nuclear membrane and vacuolar membrane tonoplast.
Structure and function rough endoplasmic reticulum.