Difference between Cell Membrane and Plasma Membrane

The cell membrane and the plasma membrane are both essential components of the cell. These are the protective layers that protect the cell from the external environment.

These two layers surround the cell organelles, as well as all ions and molecules. Although Cell Membrane and Plasma Membrane are often used interchangeably, there is a significant difference between cell membrane and plasma membrane.

Keyterms: Membrane, Plasma, Blood, Cell, Cell organelles, Cytoplasm, Protoplasm, Phospholipid, Cell division, Cilia

Also Read: What is Plasma in Blood? 

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What is Plasma Membrane?

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A plasma membrane is a membrane that surrounds cell organelles. Plasma membranes encloses a cell's cytoplasm and contents, as well as particular organelles like chloroplasts and mitochondria. A plasma membrane serves a variety of purposes depending on their location.

A plasma membrane is a type of phospholipid membrane which is found in all cells. It protects a cell's protoplasm from external environment and regulates the passage of chemicals in a cell.

Also Read: Difference between Chromosome and Chromatid

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What is Cell Membrane?

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The cell membrane is a sort of plasma membrane that encloses all the components of a cell including its cytoplasm and organelles. It protects the cytoplasm of a cell and also maintains the structure of the cell.

Plant cells also have a cell wall that further encloses the cell membrane, therefore the cell membrane is not always the outermost layer of the cell. Animal cells, on the other hand, lack a cell wall, and the cell membrane serves as a barrier between the cell's interior contents and the outside world.

The cell membrane plays a vital role in cytokinesis during the cell division. For feeding and mobility, certain species modify their membranes with cilia.

Also Read: Difference between Cytoplasm and Protoplasm 

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Functions of Cell Membrane and Plasma Membrane

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Functions of Cell Membrane

The cell membrane serves a variety of roles within the cell.

• Defending the cell from external intruders like viruses and bacteria.
• Controlling the passage of water and solutes in the cell and maintaining the correct tonicity of the cell's contents.
• Forms a selectively permeable barrier that allows some molecules to easily enter and exit the cell while preventing others from doing so.

Functions of Plasma Membrane

• The plasma membrane serves as a barrier between the cell and its surroundings. 
• It prevents particular ions and molecules from entering the cell.
• It protects a cell's protoplasm from external environment.
• It regulates the passage of chemicals in a cell

Also Read: Prokaryotic and Eukaryotic Cells 

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Difference between Plasma Membrane and Cell Membrane

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• Position- The cell membrane is solely found around the cell's contents, but the plasma membrane is also found around some cell organelles.
• Feeding and Movement- In organisms, the cell membrane can be altered to promote feeding and movement; for example, Paramecium contains cilia for eating and movement. The plasma membrane can not be altered.
• Tonicity- Cell membrane is always engaged in tonicity regulation, while the plasma membrane does not maintain the tonicity of the cell.
• Protection against invaders- The cell membrane serves as the shield for the cell from bacterial and viral invasion, but plasma membranes within the cell do not protect the cell from viral invasion. 
• Signal Transduction- The cell membrane includes the earliest receptors for signal transduction mechanisms, and thus helps signal transduction when messages from other cells are received. The plasma membranes that surround organelles are not the first stage in signal transduction, although they do play a role.
• Cytokinesis- During cell division, phospholipids in the cell membrane play a role in cytokinesis. Plasma membranes, which are not cell membranes, are not involved in this.
• Antimicrobial targets- Antimicrobial drugs can target the cell membrane of bacteria and fungi. Plasma membranes are not targeted in general, unless they are cell membranes.

Also Read:

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Things to Remember

• The cell membrane is a type of plasma membrane that surrounds a cell and all of its constituents, such as cytoplasm and organelles.
• Plasma membranes can be found forming the membranes of various organelles.
• The plasma membranes of organelles may differ from the cell membrane.
• Cell membranes and other plasma membranes have selective permeability, which allows them to control the flow of substances across them.
• During cell division, the cell membrane is involved in cytokinesis, but plasma membranes do not take part in it.
• The cell membrane serves as the shield for the cell from bacterial and viral invasion. 
• Plasma membranes within the cell do not protect the cell from viral invasion. 

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Previous Years Questions

1. A bivalent consists of...[NEET 1989]
2. A cell organelle containing hydrolytic enzymes is...[NEET 2016]
3. Water soluble pigments found in plant cell vacuoles….[NEET 2016]
4. Which of the following are not membrane - bound?….[NEET 2015]
5. Electron microscope has a high resolution power…. [NEET 1990]
6. Flagella of prokaryotic and eukaryotic cells….[NEET 2004]
7. A major site for synthesis of lipids is….[NEET 2013]
8. which one of the following colours of light so as to….[NEET 2005]
9. According to fluid mosaic model, plasma membrane is….[NEET 1998]
10. Acetabularia used in Hammerling's nucleocytoplasmic...[NEET 1988]
11. All types of plastids possess essentially….[NEET 1992]
12. An outer covering membrane is absent over….[NEET 1992]
13. Balbiani rings are the sites of...[NEET 1993]
14. the Golgi apparatus is also concerned with the...[NEET 1994]
15. Biological organisation starts with….[NEET 2007]