Endoplasmic Reticulum/Relationship with Cytoplasm

            Endoplasmic Reticulum/Relationship with Cytoplasm .
             The endoplasmic reticulum, or ER, is a double membrane system that loops back and forth. It extends from the cell membrane through the cytoplasm to the nuclear membrane. It consists of a network of membrane lamellae and tubules called cisternae; and the internal part of it is called the cisternal space otherwise known as the lumen. The ER was discovered in 1945, by Albert Claude in Belgium and Keith Porter at the Rockefeller Institute, where it was first recognized in the cytoplasm of chick embryo cells. The ER membranes are mainly located in the inner region of the cell known as the endoplasmic region. These membranes protect the inner cavity called the lumen. The lumen is a compartment for the storage of certain substances that must be kept separate from the cytoplasm. All eukaroytic cells have ER except for the red blood cells of mammals. The endoplasmic reticulum's main function is to transport materials though the cell and also serve as the site of biochemical reactions. There are two forms of ER that carry out these processes, the rough and smooth ER. .
             The rough endoplasmic reticulum is dotted with ribosome's that form granules on the surface to make it rough. These ribosome's that are bound to the rough ER synthesize the proteins. The proteins are then moved into the lumen where they are folded and carbohydrates are attached, which become glycoproteins. They are then transported to the Golgi apparatus by vesicles. .
             The smooth endoplasmic reticulum has no ribosomes bound to it and the enzymes that it deals with are involved with many different functions depending on the cell type. These functions include the synthesis of membrane components like phospholipids and fatty acids, the synthesis of steroid hormones, metabolism of carbohydrates, and the detoxification of poisons. .
             The relationship between endoplasmic reticulum and cytoplasm, besides the obvious fact that cytoplasm holds cytoplasmic organelles in the cell such as endoplasmic reticulum, is cytoplasmic streaming.