The cell wall is the outermost and non-living part of the cell. It is present only in plant cells and also seen in some fungi, bacteria and algae. The cell wall is a thick, rigid, semi-permeable membrane and has elastic properties that help them to grow in thickness over the period of time. The cell wall is metabolically inactive as it lacks receptors and is mainly involved in:
- Providing a fixed shape to the cell.
- Protects the cell from the external environment.
- Acts as a barrier between the external and internal environment.
Also Refer: Cell wall
Both, the Gram-positive and Gram-negative bacteria are the genus of bacteria family and a member of the phylum Firmicutes.
Gram-positive bacteria are the group of a heterogeneous bacteria, which appear purple in colour when they are stained in the crystal violet dye and examined under a microscope. Clostridium, Actinomyces, Mycobacterium, Nocardia streptococci, and staphylococci, are a few examples of gram-positive bacteria.
Gram-negative bacteria are the group of aerobic bacteria, which appear pink in colour when they are stained in the crystal violet dye and examined under a microscope. Vibrio, Campylobacter, Pseudomonas and members of the family Enterobacteriaceae are a few examples of gram-negative bacteria.
Also Read- Difference Between Gram-positive and Gram-negative Bacteria
Here, let us explore more information about the difference between gram-positive and negative cell wall.
Cell Wall of Gram-positive and Gram-negative Bacteria – Differences
Gram-Positive Cell Wall Vs Gram-Negative Cell Wall
| Gram-Positive Cell Wall | Gram-Negative Cell Wall |
| Layers | |
| Single layered | Double layered |
| Composition | |
| Consisting of several layers of peptidoglycan | Consisting of a single layer of peptidoglycan |
| Thickness | |
| 15 to 80 nanometers | 10 nanometers |
| Periplasmic space | |
| Small | Large |
| Outer membrane | |
| Absent | Present |
| Teichoic Acid | |
| Present | Absent |
| Porins | |
| Absent | Present |
| Lipid Content | |
| Very low (2 – 5 per cent) | High (15-20 per cent) |
| Lipopolysaccharides | |
| Absent | Present |
| Gram staining Procedure | |
| Retains the crystal violet dye and appear purple in colour | Does not retain the crystal violet dye and appear pink in colour |
These differences between the Cell Wall of Gram-positive and Gram-negative Bacteria are classified based on their structure, composition of the cell and by the procedure of Gram staining technique.
This was a brief introduction to the difference between gram-positive and negative cell wall. Stay tuned with BYJU’S to learn more in detail about the various topics like Bacteria and Bacterial Diseases at BYJU’S Biology.