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Cell Wall

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Cell wall is a rigid, protective layer that surrounds the cell membrane. The cell wall is a defining characteristic of plants cell and plays a crucial role in their function. The cell wall is composed of cellulose. The cellulose fibers are arranged in a network, forming a mesh-like structure that gives the cell wall its strength. Other components of the plant cell wall include hemicelluloses, pectin, lignin, and various proteins. The cell wall is a characteristic feature of many types of cells, including plant cells, bacteria, fungi, and some protists.

What is a Cell Wall?

The cell wall is referred to as the non-living material that protects a cell’s outer layer. According to the organism, its composition changes, and it is porous by nature. The cell wall isolates the inner elements from the surrounding environment. The cell and its organelles are also given, support, protection, and shape by it. But only, fungi and a few eukaryotic and prokaryotic creatures have this cellular component. As was already mentioned, fungi have cell walls as well, but they are composed of chitin, a glucose derivative that is also present in arthropod exoskeletons

Plant Cell


 Additionally, they offer structural support and guard against desiccation, just like plant cell walls do. Moreover, bacteria have cell walls. They differ chemically from the cell walls found in plants and fungi, though. Peptidoglycans, which are substantial polymers, make up bacterial cell walls. Prokaryotes have cell walls that act as a type of defense and stop lysis. Prokaryotic cell walls have two layers structurally:

  • Peptidoglycans make up the inner layer.
  • Lipopolysaccharides and lipoproteins make up the outermost layer.

Eukaryotic cells have a unique nuclear membrane and a distinct nucleus. Additionally, it has membrane-bound organelles that are absent from prokaryotic cells. Another significant distinction is that only plants have cell walls; other eukaryotic creatures, such as animals, have not.

Cell Wall Structure

Plant Cell wall Structure


The cell wall, which is located on the next membrane of the cell also known as the plasma membrane, is the outer layer of a cell. All plant cells, as well as those of, bacteria, and archaea, contain a cell wall. Animal cells have a wavy form, which is mostly caused by the absence of a cell wall. Cell walls typically have different compositions depending on the organism. Plant cell walls typically consist of three layers and a network of carbohydrates like pectin, cellulose, and hemicellulose, as well as trace amounts of other minerals and structural proteins. There are three main layers:

  • Basic Cell Wall or primary cell wall
  • Middle Lamella
  • Additional Cell Wall or secondary cell wall
Structure of Cell Wall


Primary Cell Wall

The primary cell, which was the first to build a cell wall, is located nearest to the interior of the cell. Because cellulose makes up the majority of it, the wall may expand to accommodate growth. Pectic polysaccharides and matrix proteins are present in a number of primordial cells. It is also thinner and more porous than the other coats.

Middle Lamella

The middle lamella, which is also the top layer, serves as a connecting point and holds the neighboring cells together. Pectin makes up the majority of this stratum. However, other materials can also be discovered, including proteins and lignin.

Secondary Cell Wall

Once the cell has fully developed, the secondary cell wall is created inside the primary cell wall membrane. Cellulose and lignin are components of some types of cells (particularly those found in xylem tissues), and they contribute extra stiffness and waterproofing. Additionally, this layer gives a cell its typical square or rectangular shape. In addition to being the thickest layer, it allows permeability.

Functions of Cell Wall

The cell wall serves a variety of crucial roles as an integral part of the plant cell. The following are amongst the most significant cell wall activities noticed:

  • Plant cell walls have distinct shapes, are strong, and are rigid.
  • Additionally, it shields users from mechanical stress and bodily trauma.
  • It aids in limiting cell growth brought on by water intake.
  • It aids in preventing cell water loss.
  • Furthermore, it is in charge of moving materials within and outside the cell.
  • Between the internal cellular components and the outside world, it serves as a barrier.

Differences between the Cell Wall and Cell Membrane

  1. Cell walls would be present in the case of plants and the cell membrane is present in every cell. For example humans, plants, etc.,
  2. Cell wall thickness would be 0.1 micrometers to several micrometers in thickness and the cell membrane would be 8-11 nanometers in thickness.
  3. The cell wall would be the plant cell’s outer covering and the cell membrane would be the animal cell’s outer covering.
  4. The cell wall would consist of chitin, sugars, glycoprotein, etc., Whereas the cell membrane would consist of lipids and carbohydrates.
  5. The cell wall would be in a fixed shape, but the cell membrane would change its shape.
  6. Cell wall thickness would be increased time by time, but the cell membrane would be the same all the time.
  7. The cell wall would be fully permeable, but the cell membrane selectively permeable.
  8. The function of the cell wall would be protective, and the cell membrane would be a division of cells, sexual reproduction, motility, etc.,

FAQs on Cell Wall

Q1: How Do Cell Walls Work?


A hard, exterior layer created especially to offer rigidity and structural support is known as a cell wall. Additionally, it protects the inside parts of the cell from the outside environment and preserves them intact.

Q2: What are two properties of a Cell Wall?


Folowing are the properties of Cell Wall:

  • Provide Rigidity to the cell i.e., structural Support
  • Provide protection to the cell

Q3: What are the Cell Wall’s three Layers?


The primary cell wall, secondary cell wall, and middle lamella are the three layers that make up a normal plant cell wall..

Q4:  What really is the Cell Wall’s Primary Purpose?


The upper surface of a plant cell is the cell wall. It gives the plant structure mechanical stability and stiffness.

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Last Updated : 06 Jun, 2023
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