In this article we will discuss about the structure of plant cell which is covered by cell wall. This will also help you to draw the structure and diagram of plant cell.
1. A plant cell (Fig. 291) is more or less a polyhedral structure limited on the outside by a rigid limiting membrane called cell wall.
2. Inside, it contains the protoplast. The contents of each living cell is known by the name protoplast.
3. The cell wall is not living while the protoplast is living.
4. A membrane which bounds the protoplasm of the cell is known as plasma membrane or cell membrane. It is made of lipids and proteins. It is found in all plants and animals. In plants, the plasma membrane is covered by a cell wall. The cell wall is absent in animal cells.
5. The basic substance, protoplasm, is not homogeneous.
6. Embedded in the protoplasm is a fairly large, spherical body, the nucleus (pl. nuclei).
7. The protoplasm surrounding the nucleus of the cell is usually referred to as the cytoplasm.
8. There are other smaller disc shaped bodies embedded in the protoplasm called the plastids.
9. The studies under the electron microscope have revealed that the cytoplasm contains a number of other much smaller inclusions which were not easily made out under the light microscope. These include mitochondria (sing, mitochondrion) or chondriosomes, endoplasmic reticulum, Golgi apparatus and ribosomes which usually occur in groups called the polysomes.
10. Cytoplasm has a system of tubules from the plasma membrane outside to the nucleus inside.
11. In very young conditions, the cell lumen or cavity is filled with protoplasm. But as the cell matures a corresponding amount of protoplasm is not synthesized to keep pace with the increase in its volume and so vacuoles (spaces in the protoplasm) appear.
12. The vacuoles are filled with a watery fluid which is a solution of various inorganic substances absorbed by the plant from outside and organic substances which are synthesized by the plants.