[Biology Class Notes] on Difference between Cell Membrane and Plasma Membrane Pdf

The cell in the human body is a very intriguing thing to study to say the least. It is a brilliant example of how smart the human body is and what exactly it does to keep itself alive. The human cell was initially known to have lesser components than what we know now. We know that the human body is a wonderful machine that does most of its job involuntarily without our involvement in it. The cell is also the same. The cell carries out most of its function without our conscious control over it and leads to the survival of our bodies. There are certain components of a cell. In this article we will be taking a look at two of the most important parts of the cell structure. The Cell Membrane and the plasma membrane. 

Both Cell membrane and plasma membrane are integral parts of cell structure. These two components are the protective layers that protect the cell from external shocks.

The cell organelles, along with all the ions and molecules, are surrounded by these two layers. Often these two terms are used synonymously, but the difference between cell membrane and plasma membrane is substantial. 

What is Plasma Membrane?

Plasma membrane is a kind of phospholipid membrane, present in all cells. It protects the protoplasm of a cell from outer hazards and checks the movements of molecules in and out of a cell. 

What is Cell Membrane?

Cell membrane is a thin multifaceted layer that acts as a barrier between the inner parts of a cell and the other part. It protects the cytoplasm of a cell and also provides shape to a cell. This particular membrane is a part of all cells, animals and plants. 

However, in plant cells, algae and fungi, a cell wall is present and it envelopes the membrane. It is a kind of plasma membrane. 

Once you know the basic concepts of these membranes, it will be easier for you to differentiate between plasma membrane and cell wall. Let’s begin!

Plasma Membrane vs Cell Wall

There are a few differences between plasma membrane and cell wall. Some of them are discussed below. 

Plasma Membrane

Cell Wall

1. Definition

Plasma Membrane is a thin layer, sized 5-10 nm, that secures the interior of a cell from extracellular space. 

Cell wall is the rigid outermost layer of a cell, sized 4-20 um. It supports the cell to continue its inner mechanism. In some plants, it consists of three layers.  

2. Presence

The plasma membrane is present in all kinds of cells.

Cell wall is present exclusively in plant, bacteria, fungi, algae cells. 

3. Structure

The plasma membrane is thin and is visible only under an electron microscope.

The hard Cell wall is visible through a light microscope. 

4. Composition 

The plasma membrane is made up of lipids, proteins, and carbohydrates

The cell wall consists of chitin (fungi), cellulose (plants) and peptidoglycan (bacteria)

5. Type of organism 

The plasma membrane is living and metabolically active. 

The cell wall is non-living and inactive

6. Receptors

The Plasma Membrane contains receptors

Cell Wall does not contain receptors

7. Permeability

The plasma membrane is semi-permeable

Cell wall is entirely permeable. 

8. Nutrition

It requires nutrition to survive

It does not need nutrition, rather a deposition from cell organelles

9. Texture

The thickness of the plasma membrane or cell membrane remains unchanged throughout its life

The thickness of the cell wall grows with time

10. Functions

Significant functions of plasma membrane include 

  • Protection of protoplasm, 

  • Assist in communicating between cells, and 

  • Keep track of molecular movements.

The cell wall provides shape to a cell, takes part in morphology, and maintains the osmotic environment of a cell. It protects the inner organelles from outside forces as well. 

Apart from these, the most fundamental difference between plasma membrane and cell wall is that the former one is present in the inner lining of all cells while the latter one protects the membrane (specific cells).  

MCQ: which organelle participates in cell wall synthesis?

  1. Chloroplast

  2. Mitochondria

  3. Lysosome

  4. Golgi apparatus

Ans. 4

Conclusion

We hope that students understood details about the functions, texture, permeability, composition, and structure of the cell membrane and the plasma membrane and also how different they are from each other. Keep this article handy for future use!

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