Endoplasmic reticulum

Mean:
        Endo                   inside
        Plasma                cytoplasm or cell
        Reticulum          network
Definition:
                  "it is a double membrane-bounded structure present in the network from throughout the cytoplasm of the eukaryotic cell".
Discovery: 
                fist discovered by o reported by the porter in 1945
Chemical Composition:
                                      chemically composed of proteins, lipids and little amount of cholesterol.
Types:
          on the base of physical structure, they have two types.
1-Rough Endoplasmic Reticulum:
Definition:
"it is the type of E.R to which ribosome are attached together and appears granular and rough in the form"
Diagram: 

2-Smooth Endoplasmic Reticulum:
Definition:
                "it is the type of E.R to which ribosomes are not attached and appeared smooth in the form".
Digram:




Function:
1-They help in the transport of material within the cell.
2-RER  involved in protein synthesizes.
3-SER helps in detoxification of drugs in the liver.
4-SER helps in liver metabolism.
5-SER plays a role in muscle contraction.