Electron micrograph showing the two parallel memberanes of the ER.

The endoplasmic reticulum or ER is located in the cytoplasm.

It is a membrane system that extends throughout the cell.

In electron micrographs, the ER appears as two parallel membranes.

Electron micrograph showing the two parallel memberanes of the ER.

The endoplasmic recticulum is the source for the membrane material used to create the vacuole, Golgi bodies and microbodies (like protein bodies and glyoxysomes).

Electron micrograph identifying the cell wall, plasmadesmata, and ER with attached ribosomes moving around and possible through plasmadesmata.

The ER is also thought to function in cellular communication.

ER are found associated with the nuclear envelope and are even seen extending through the plasmadesmata between cells.

There are two types of ER

Electron micrograph with rough ER identified.

Rough ER have ribosomes attached to them and are actively involved in protein synthesis.

Electron micrograph with smooth ER identified.

Smooth ER are not associated with ribosomes.