Question

List the functions of rough and smooth endoplasmic recticulum and Golgi bodies.

Answer 1

Functions of Rough Endoplasmic Reticulum (RER)

1. It contains ribophorins for providing attachment to ribosomes.
2. It bears enzymes in the region of pores for modifying polypeptides synthesised by attached ribosomes, e.g., glycosylation.
3. It synthesises serum proteins, membrane proteins and a number of other proteins.
4. Proteins and enzymes synthesised by ribosomes enter the channels of RER both for intracellular use as well as secretion.
5. It provides enzymes precursors for the formation of lysosomes by Golgi complex.
6. SER can develop from RER by discarding ribosomes.

Functions of Smooth Endoplasmic Reticulum (SER)

1. It is responsible for synthesis of fats inside the cells of adipose tissue, formation of sphaerosomes, synthesis of glycogen as well as glycogenolysis in liver cells, synthesis of sterol, etc.
2. As sarcoplasmic reticulum, it stores $C{a}^{2+}$ for release during muscle contraction.
3. It takes part in detoxification of toxic chemicals with the help of cytochrome P-450.
4. Synthetic products of RER pass on to Golgi complex through SER.

Functions of Golgi bodies

1. All glandular cells depend upon Golgi complex for concentrating and packaging their products inside a soluble protein coat visible as dark staining under electron microscope.
2. Golgi complex brings about membrane transformation, that is, converting one type of membrane into other types.
3. Proteins synthesised by the rough endoplasmic reticulum and lipids synthesised by smooth endoplasmic reticulum reach the cisternae of the Golgi apparatus. Here, they combine with carbohydrates to form glycoproteins and glycolipids.