Cell wall definition
Cell Wall Definition

Cell Wall Definition, Structure, and 11 Functions

In a hierarchy of living things, the cell is the smallest part compared to others. Similarly, plants have cell tissue to sustain their lives. But, did you know that in the cell itself has parts that surround it, one of which is the cell wall. So what is a cell wall definition, structure, and functions?

In plant cells, the cell membrane is coated by a cell wall that is a rigid dividing wall of the outermost part of the plant cell that limits the space of the cell to enlarge, thus making the cell unable to move and develop freely.

Cell Wall Definition

The cell wall is the layer outside the cell membrane that surrounds a particular cell type and limits the space of the cell to expand. Cell walls are a distinctive feature found in plants, fungi, algae, and bacteria. The cell wall is not present in animals and protozoa. Cell walls have flexible, strong structures, but some are rigid.

The cell wall causes cells to not be able to develop and move freely, as in plant cells. But this has a positive impact because the cell wall can provide protection, support and filters to the structure and function of the cell itself. The cell wall can also prevent excess water pressure when entering the cell.

Cell Wall Structure

Each organism has a different cell wall structure, for example, the structure of plant cell walls usually consists of carbohydrate polymers (cellulose, lignin, pectin, and hemicellulose). The cell wall structure of a fungus consists of chitin.

The cell wall structure in algae consists of simple pectin, glycoproteins, and sugar saccharides. Meanwhile, the cell wall structure in bacteria consists of peptidoglycans (glycoproteins). The following is a complete explanation of the structure of cell walls in plants, algae, fungi, and bacteria.

Cell wall structure of plants

Plant cells have thin and flexible primary cells during the growth process. The primary cell wall is located between the secondary cell wall and the central lamella. The primary cell wall consists of hemicellulose, pectin and glycoproteins. The secondary cell wall is inside the cell wall.

A secondary cell wall is a cell wall that has a thick layer and a strong texture. A**dult cells form secondary cell walls. The secondary cell wall consists of cellulose, lignin, and hemicellulose. Meanwhile, the middle lamella is the outer layer of the cell wall. Central lamella contains a lot of pectin that binds to other cells.

Plant cell walls can help keep turgor pressure under control so that cells don’t swell and burst when water is completely different. When the turgor pressure is gone, the plant is destroyed because the turbine pressure makes the plant cells stiff.

Cell wall structure of fungi

The cell wall in the fungal group consists of chitin, a glucose derivative similar to the structure of cellulose. Chitin is the same molecule that occurs in animals in the rigid exoskeleton.

Like crustaceans and insects. The chitin layer is very good. In addition to the cell walls of fungi, there are also proteins and lipids as well as glucose (other glucose polymers).

Proteins found in the cell walls of fungi are called hydrophobins. Hydrophobins ensure cell strength, regulate the movement of water entering the cell and help fungal cells to the surface. The cell wall in the fungal group is the outer layer and surrounds against the cell membrane.

Cell wall structure of algae

Some types of algae, for example, green algae, have cell walls with plant-like structures. Other algae such as red algae and brown algae have cellulose and other polysaccharides or fibrils.

A group of algae known as diatoms has cell walls made of silica. In the cell walls of algae there are other important molecules such as mailman, Xylan, and alginic acid.

Cell wall structure of bacteria

The cell wall in bacteria usually consists of porous polysaccharide peptidoglycan that are passed by small molecules. In bacteria, the cell wall and cell membrane are known as cell membranes.

The cell wall is an important part of bacterial survival, as it serves to protect bacterial cells from internal turgor pressure and give bacteria, which are cells, mechanical structures.

Bacteria have a higher concentration of molecules than the external environment, so the cell wall in the bacteria can prevent water from flowing into the cell. Cell walls of bacteria that have different thicknesses that can cause in gram staining.

Cell Wall Function

The cell wall has a variety of functions.

  • Maintain/determine the shape of the cell.
  • Supports and powers mechanically (allow plants to grow tall, etc.).
  • Prevents cell membranes from breaking in a hypotonic medium or turgor pressure.
  • Controls the rate and direction of cell growth and regulates the contents of the cell.
  • It is responsible for the structure of plant forms and controls plant morphogenesis.
  • It has a metabolic role.
  • Provide physical protection from insect and pathogen attacks.
  • Storage of carbohydrates, which is one component of the cell wall that can be reused in other metabolic processes. So, on one side of the cell wall serves as a storage shed for carbohydrates.
  • As an economical product, where the cell wall is very important to produce products such as paper, fiber, wood fiber, energy sources, boards and even as a basic ingredient in our dietary food products.
  • Tubes for long-distance transportation.
  • Physiological and biochemical activities on the cell wall play a role in communication between cells.

Read also:
What Is The Function of An Enzyme? Definition, Purposes, Functions, and How It Work


Last Updated on August 14, 2021 Reviewed by Market Health Beauty Team


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