Endoplasmic Reticulum

The structure and formation of the ER outlines how the ER assists in protein and lipid synthesis among other biological processes. There are two types of ER, as seen in Figure 2, the rough ER and the smooth ER. The name of the rough ER originates from the fact that ribosomes spot the outer membrane. In contrast, the outer membrane of the smooth ER contains no ribosomes. Depending on the type of cell, the ratio of smooth to rough ER will vary drastically (“The Endoplasmic Reticulum”). Both types of ER, however, have a similar structure of a large, continuous membrane that folds to create intramembrane spaces of different sizes. This intramembrane space is known as the cisternal space and connections exist between the cisternal spaces themselves in addition to the nucleus. The whole organelle is supported by the cytoskeleton of the cell which allows the ER to maintain its structure (English).