F.3 Biology (Cell)

rough endoplasmic reticulum (rER) IS NOT UESD TO RELEASE ENERGY!!!

rER is parts of the endoplasmic reticulum to which ribosomes are attached on
the cytoplasmic side;
It involved in the synthesis of proteins
The synthesized proteib will be transfered to golgi apparatus for packing and modification. Several kinds of protein will be synthesized such as secretory proteins, lysozome, enzyme, membrane proteins, etc...

The smooth endoplasmic reticulum (SER) has functions in several
metabolic processes, including synthesis of lipids and steroids,
metabolism of carbohydrates, regulation of calcium concentration, drug
detoxification, attachment of receptors on cell membrane proteins, and steroid metabolism. Protein synthesis is not its function actually.

To conclude, endoplasmic reticulum have the main functions as the following:
1. it forms an extensive membranous system that acts as a cytoplasmic skeleton to support the cell.
2. intricate channels of the ER facilitate the transport of materials inside the cell
3. rER for protein synthesis
4. large surface area for enzyme attachment to allow metabollic reactions to take place
5. sER for formation and transport of lipids and steroids

with ribosomes attached to the surface are calles rough ER

without are calles smooth ER


Rough ER =the sites of protein synthesis

Smooth ER = involved in the synthesis & transport of lipids