Difference Between Cell Wall And Cell Membrane
In this Article you will know about cell wall and cell membrane.
What is Cell :-
The cell (Latin word means ‘little room‘) is the basic structural, functional and biological unit of all known living organisms. Cells may be compared to the bricks which are assembled to make a building. Cells are also assembled to make the body of every organism.
Difference Between Cell Wall And Cell Membrane
| Cell Membrane | Cell Wall |
| Present In All Cells | Present only in plants , bacteria , fungi and algae |
| It is Semi- Permeable. | It is fully permeable |
| Main Function Is to Protect Protoplasm. | Main function is to protect cell membrane and maintains shape of the cell. |
| It is alive and it is active metabolically. | Non-living and inactive . |
| Made up of lipids , Protein and Carbohydrates. | Made up of peptidoglycan in Bacteria ) , chitin ( in fungi) and cellulose in plants. |
Cell Wall
The cell wall is a rigid (non-living) but flexible covering of the cell which is located outside the cell membrane and provides shape and structural support to the cells. It also protects the cells from the outside attack and infection. Cell walls are particularly found in plants, fungi, bacteria, algae and some archaea. Animals and protozoans do not have cell walls.
Cell walls are made up of various materials depending on the species like
- Bacterial cell wall is made up of peptidoglycan.
- Fungi’s cell wall is made up of the glucosamine polymer chitin.
- Algae’s cell wall is made up of glycoproteins and polysaccharides.
- Plant’s cell wall is mainly made up of cellulose, which provides structural strength to it.
Structure of Cell Wall
Cell wall constitutes following three layers in its organisation
Outermost Layer
Also called middle lamella, rich in pectins, forms interface between adjacent plant cells and glue them together.
Primary Cell Wall
Thin flexible layer, forms when the cells grow, it is single layered.
Secondary Cell Wall
Thick layer, forms when cell is fully grown, not found in all cells, it is 2-3 cell thick
Functions of Cell Wall
- Cell wall permits the cell of plants, fungi and bacteria to withstand without bursting by acting as a pressure vessel.
- It also helps cell to tolerate much greater changes in the surrounding medium as compared to animal cells.
Cell Membrane or Plasma Membrane
This is the outermost covering of cell, separating the contents of the cell from its external environment. Plasma membrane is made up of lipids (major content is phospholipid) and proteins. Structurally, it is a thin, flexible and semi-permeable or selectively permeable membrane. The cytoplasm and nucleus are enclosed within the cell membrane. Animal cells, plant cells, prokaryotic cells and fungal cells all have cell membranes as their outer covering except viruses which are devoid of cell membrane.
Functions of Cell Membrane
- Its major function is to maintain shape of the cell by providing support to it.
- It protects the interior components of the cell by selectively allowing the movement of certain substances (ions, organic molecules) in and out of the cell. This function is regulated by selectively permeable nature of the membranes.
- The flexible nature of the cell membrane allows the cell to engulf food and other substances from the surrounding environment and this process of intake is known as endocytosis, e.g., in Amoeba.
- It also serves as a base for the attachment of cytoskeleton in some organisms and the cell wall in others.
- It performs various other functions in a cell such as cell adhesion, ion conductivity and cell signaling.
Difference Between Cell Wall And Cell Membrane
Note :-
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Difference Between Cell Wall And Cell Membrane