The living contents of the eukaryotic cells are divided into nucleus and cytoplasm. It is a colorless, transparent and semifluid substance. Cytoplasm is found around the nucleus. It contains water, proteins, carbohydrates, lipids and other substances. Cytoplasm maintains the life of a cell. All chemical process takes place in the cytoplasm. These living contents (nucleus and cytoplasm) collectively form protoplasm.
The cytoplasm has two parts:
a. Organelles and Insoluble Products
It contains different cell organelles like mitochondria, Golgi bodies, endoplasmic reticulum, lysosomes etc. It also contains insoluble waste and storage products.
The soluble part of the cytoplasm is called cytosol. It forms the ground substances of the cytoplasm. Chemically, it has about 90% water. It contains all fundamental molecules of the cells. These molecules are present in two forms:
- True Solution: the small molecules and ions from a true solution.
- Colloidal Solution: some large molecules from a colloidal solution. The colloidal solution is present in two forms.
- Sol: It is the part of cytoplasm present in the peripheral region. It is more transparent and less viscous and also known as “Sol”.
The non-viscous colloidal solution is called sol. It is present in liquid form. For example, Milk.
- Gel: It is the part of cytoplasm present in the central region. It is less transparent and more viscous and also known as “Gel”.
The viscous colloidal solution is called gel. It is present in the form of semi-solid. For example, Butter.
Functions of Cytoplasm
Cytoplasm performs following functions:
- It acts as a storage house. Most of the important compounds like starch are stored in the cytoplasm.
- Some metabolic processes like glycolysis (breaking or glucose) take place in the cytoplasm.
- The cytoplasm contains several cell organelles like Mitochondria, Golgi-bodies, Endoplasmic Reticulum and Lysosomes etc. These cell organelles perform many important functions of the cells.
- Cytoplasm shows streaming movements. This is an active mass movement of cytoplasm. Many free floating organelles like mitochondria move in the cytoplasm due to these streaming movements.