What is endoplasim reticulum?
the endoplasmic reticulum (ER) is repsonible for the production
of the protein and lipid components of most of the cell's
organelles. The ER contains a great amount of folds - but the
membrane forms a single sheet enclosing a single closed sac. This
internal space is called the ER lumen. The ER is additionally
responsible for moving proteins and other carbohydrates to the
Golgi apparatus, to theplasma membrane, to the lysosomes, or
wherever else needed.
There are two types of ER - rough, which is coated with
ribosomes, and smooth, which isn't. Rough ER is the site of protein
synthesis. The smooth ER is where the vesicles carrying newly
synthesized proteins (from the rough ER) are budded off.