ENDOPLASMIC RETICULUM - Smooth ER The smooth ER is more...


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ENDOPLASMIC RETICULUM Extensive maze of branching membranes that extends throughout the cytoplasm. Evidence suggests that the ER is continuous with the plasma membrane and with the outer membrane surrounding the nucleus. ( Drawing ) [Intramembrane network] Therefore, the membranes of the ER divide the cytoplasm up into interconnected compartments in which different types of reactions take place. The ER plays an important role in the synthesis of proteins and some lipids. Expanded regions of the ER may serve as storage areas. The ER also functions as a system for transporting materials from one part of the cell to another.
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Unformatted text preview: Smooth ER The smooth ER is more tubular and its outer membrane surfaces have a smooth appearance. It is the primary site of phospholipid, steroid, and fatty acid metabolism. The smooth ER also contains enzymes that detoxify harmful chemicals, breaking them down into water-soluble substances that can be excreted. Rough ER The Rough ER has a more granular appearance under EM due to the presence of ribosomes. Ribosomes of course serve as the sites of protein synthesis and can be found assoc. with the ER or free in the cytoplasm. RER is especially abundant in cells that synthesize proteins destined for exocytosis....
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