Endoplasmic reticulum (structures contained in cells)
The Endoplasmic reticulum is a functional structure within a cell (organelle).
It is basically a membrane enclosing a lumen (empty space) and is divided into rough endoplasmic reticululum (RER) and smooth endoplasmic reticulume (SER).
The ER is highly convoluted which allows a large contact surface for ribosomes to attach (or reactions to occur) as well as an organized peptide storage area.
The RER does many more things as it contains ribosomes, which are the protein-producing factories of a cell.
The RER is therefore involved in the production storage and packaging of proteins produced in the cell and are sent to the Golgi Apparatus.
The SER produces liposoluble molecules such as lipids, steroids and phospholipids – phospholipids are the main constituent of the cell membrane.
Rosacea could be induced by stress on the ER (to read more, click HERE)