Plasma Membrane vs. Cell Wall

The basic difference between the cell wall and plasma membrane is that the cell wall is not found in animal cells. It is present in plants and fungal cells forming the outermost boundary of their cells while cell membrane is found in all the cells including plants as well as animal and fungal cells.

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Plasma Membrane vs. Cell Wall

There are many differences between the cell wall and plasma membrane, but the key difference is that cell wall is present only in the plant cells while cell membrane or plasma membrane is present both in plants and animal cells. All the fungi and bacterial cells also have a cell wall.

The plasma membrane is made up of proteins and lipids and a few carbohydrates while the cell wall is composed of cellulose in plants, peptidoglycan in bacteria and chitin in fungi. Plasma membrane does not allow all the substances to pass through it, so it is selectively permeable while the cell wall is freely permeable. It allows all types of molecules to pass through it.

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The plasma membrane is thin, soft and delicate while the cell wall is rigid and thick. It is the layer that actually forms the outermost boundary of the cell if present. In the animal cells, the cell wall is not present, so the cell membrane is the outermost boundary of their cells. The plasma membrane is 5-10nm wide while the cell wall is 4-20um wide. Plasma membrane can be visualized by electron microscope while the cell wall can be visualized by a light microscope because it is thick.

Plasma membrane has a certain type of receptors that help the cell in communication with other cells while cell wall has no receptors. The plasma membrane is a metabolically
active entity. A cell cannot survive without its cell membrane while the cell wall is a dead thing. No metabolic reactions take place in it. A cell can survive even if its cell wall is removed.

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The thickness of the cell wall increases with the passage of time while the thickness of the cell membrane remains same throughout life. The cell membrane is living, so it
needs proper nutrition form cell for its survival and functions while the cell wall does not require nutrition because it is a dead entity.

The plasma membrane is also known as a cell membrane or plasmalemma while there is no alternate name for cell wall. The prime function of the cell wall is to protect the cell, provide it
structural support and protect it from over-expanding. It gives rigidity to the cell and enables the cell to tolerate external shock and forces. Thus it maintains the cellular morphology. The
primary function of the cell membrane is the protection of the inside of the cell and regulation of the passage of molecules because it is semipermeable. It also separates the protoplasm from the outer
environment. It also helps in communication between cells.

Comparison chart

BasisPlasma Membrane Cell Wall
DefinitionThe plasma membrane is a delicate and thin covering present outside the protoplasm
in all cells.
The cell wall is a rigid and non-flexible
outermost boundary present in all the plant, fungal and bacterial cells.
CompositionIt is made up of proteins, phospholipids and some
carbohydrates.
It is composed of cellulose in plants, peptidoglycan
in bacteria and chitin in fungi.
Permeability It is freely permeable.It is selectively permeable.
ThicknessIt is thin and flexible. Its thickness is 5 to 10nm.It is rigid and thick. Its thickness is r to 20um.
Outermost boundary It is the outer most boundary in animal cells.It is the outermost boundary in the plants,
bacterial and fungal cells.
Other names It is also known as a cell membrane or plasmalemma.It has no alternate name.
Metabolism It is a living
entity and metabolically active.
It is a dead thing. No metabolism takes place in it.
Nutrition It requires nutrients for its survival and
functions.
It does not need nutrients.
Result of removal If cell membrane is removed, a cell cannot survive.If the cell
wall is removed, the cell can survive easily.
Effect of age on the thickness Its thickness remains same throughout with the
passage of time.
Its thickness increases with the passage of time.
Primary function Its main function is to protect the inside of the cell and regulate the passage of molecules.Its main function is to maintain the structure of the
cell and protect it from external
forces.
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What is Plasma Membrane?

The plasma membrane is a thin and delicate structure forming the outer boundary of the cell. It covers the cytoplasm. It is the outermost boundary in the cells of animals, but in the plant
cells, a boundary next to it is presently called cell wall. Plasma membrane also known as cell membrane is selectively permeable layer allowing the passage of smaller molecules but
inhibits the large molecules. It also helps the cell in communication with the neighbouring cells. Its structure can be explained as; it is actually a phospholipids bilayer sandwiched between inner and outer protein layers. Carbohydrates are also present in it.

It is a soft and flexible structure because of the presence of high content of lipids in it. It is hydrophobic and lipophilic, so lipid molecules or uncharged particles pass through it easily and rapidly while hydrophilic or charged particles face difficulty while passing through it. It is a living entity. Several metabolic reactions take place in it, so it needs necessary nutrients for its survival. If the plasma membrane of a cell is removed, it will be unable to survive.

The main function of the cell membrane is to support and protect the cytoplasm from the outer environment and control the
traffic passing through it.

What is Cell Wall?

The cell wall is actually a dead or non-living boundary covering the cells of plants, fungi and bacteria. It is made up of cellulose in plants, peptidoglycan in bacteria and chitin in fungal cells. Unlike the plasma membrane, it is freely permeable. It is a rigid entity. Not metabolic reactions take place in it. Its prime function is to give support to cell and maintain its morphology. It prevents over-expansion and burst of the cell. Since the cell wall is a non-living thing, a cell can survive easily even if its cell wall is removed. A cell with its cell wall removed is called protoplast. Cell wall can be visualized through a light microscope because of its thickness.  The thickness of the cell wall continues to increase with the age of the cell because it is dead. So materials continue to add in it and thickness grows.

Key differences

  1. The plasma membrane is present in all types of cells while the cell wall is present only in the plant, fungal and bacterial cells.
  2. The plasma membrane is flexible and thin while the cell wall is a  rigid and thick entity.
  3. Metabolic reactions occur in the plasma membrane while no metabolism occurs in the cell wall.
  4. The plasma membrane is selectively permeable while the cell wall is freely permeable.
  5. The plasma membrane is composed of phospholipids, proteins and carbohydrates while the cell wall is made up of peptidoglycan, chitin
    or cellulose.

Conclusion

Cell wall and plasma membrane have the prime importance in the structure of a cell also necessary for the functions of the cell. Since both are the boundaries of the cell, so it is mandatory to know
the difference between them. In the above article, we learned about the differences between the plasma membrane and cell wall.

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