CBSE Class 9 Answered

The endoplasmic reticulum (ER) is a eukaryotic organelle that forms a large, interconnected, membrane network of tubules, vesicles and cisternae. The phospholipid membrane encloses a space, the cisternal space (or lumen). The ER works closely with the Golgi apparatus and ribososmes. The ER may also look different from cell to cell, depending on the cell's function

There are two types of ER. They are rough ER and smooth ER.

They both have the same types of membranes but they have different shapes and rough ER has ribosomes attached. Rough ER looks like sheets of bumpy membranes while smooth ER looks more like tubes.

Smooth ER has its purpose in the cell. It acts as a storage organelle. It is important in the creation and storage of steroids. It also stores ions in solution that the cell may need at a later time. SER is also important in detoxification of harmful substances.

Rough ER is very important in the synthesis and packaging of proteins. Some of those proteins might be used in the cell and some are sent out.