Endoplasmic Reticulum

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Smooth Endoplasmic Reticulum

The smooth endoplasmic reticulum functions as a packaging system, and unlike its counter part, the rough endoplasmic reticulum, it does not have ribosomes attached to it. The endoplasmic reticulum works closely with the Golgi apparatus, ribosomes, RNA, mRNA, and tRNA. It creates a network of membranes found through the whole cell. The endoplasmic reticulum may also look different from cell to cell, depending on the cell's function. Smooth endoplasmic reticulums are shaped more like tubes. The endoplasmic reticulum is important because it plays a big part in a cell because it acts like a storage organelle. It helps create steroids and proteins then stores them. In muscle cells, it stores calcium. Smooth endoplasmic reticulum is also used to synthesise lipids. This synthesis creates lipoproteins which is found in the liver. The endoplasmic reticulum also stores glycogen. The endoplasmic reticulum consists of tubules and vesicles that branch forming a network. In some cells there are dilated areas like the sacs of rough endoplasmic reticulum. The endoplasmic reticulum is folded and stacked layer upon layer within the cell and is connected to the cell's nuclear membrane Another function of the endoplasmic reticulum is to control the movement of newly synthesized proteins to their proper locations in the cell or to the membrane to be sent outside the cell. This is done by a process called budding, where small vesicles of smooth endoplasmic reticulum are cut off to carry the proteins to their new spots in the cell. It also stores ions in solution that the cell may need at a later time. The endoplasmic reticulum allows molecules to be moved between the lumen and the cytoplasm, and since it is connected to the double-layered nuclear envelope, it gives a route between the nucleus and the cytoplasm. In muscle cells the endoplasmic reticulum releases calcium to trigger muscle contractions. The endoplasmic reticulum also has a role in...
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