Difference between Gram Positive and Gram Negative Cell Walls
The cell wall of gram-positive bacteria is consisting of thick layers of peptidoglycan Whereas the cell wall of gram-negative bacteria is consisting of thin layers of peptidoglycan.
Jasdeep Bhatia13 Mar, 2024
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Difference between Gram Positive and Gram Negative Cell Walls: Gram Positive and Gram Negative cell walls have distinct structures, components, and functions that make them different. While both cell walls are essential for cell structure and protection, they are composed of different components and perform different functions.
In our daily life, we interact with bacteria which we cannot see, but when they cause harm, we immediately get a strike in our mind that we may have to suffer from bacterial disease. There are mainly two types of bacteria in our environment- Gram-positive and Gram-negative. This blog will discuss the structure, components, and function of Gram Positive and Gram Negative cell walls and explore their differences.Difference Between DNA and RNA
Gram-Positive Bacteria
The cell wall consists of several layers of peptidoglycan, forming a tough and thick structure. Its cell wall also has teichoic acids and phosphate. Gram-positive bacteria retain the gram stain and show a visible violet colour after using iodine and ethanol alcohol.Differences between Fungi and Lichen
Gram-Positive Cell Wall Struc ture
It comprises a thick layer of peptidoglycan, a polymer of amino sugars and short peptides. This layer is surrounded by a cytoplasmic membrane composed of lipids and proteins. The peptidoglycan layer protects from environmental factors like dehydration and chemical attack. In addition, it helps maintain the cell's shape and integrity. Gram-positive bacteria can also contain additional layers of material, such as teichoic acids, lipoteichoic acids, and capsular polysaccharides, which can contribute to the bacteria's antibiotic resistance.Difference Between Centipede And Millipede
Gram-Negative Bacteria
Gram-negative bacteria have a cell wall comprising an outer membrane of lipoproteins, phospholipids, and several layers of peptidoglycan. Peptidoglycan is located in the fluid-like periplasm between the plasma and outer membranes, whereas periplasm contains proteins and degrading enzymes that help transport molecules. The cell walls of the gram-negative bacteria do not contain teichoic acid. As the porins are present in the outer membrane, it is permeable to nutrition, water, food, iron, etc. Gram-negative bacteria are resistant to antibiotics because their cell wall is impenetrable. Gram-negative bacteria are stained using counterstain like safranin but de-stains due to the alcohol wash. So, when viewed under a microscope, they look pink in colour.Difference Between Diapause And Hibernation
Gram-Negative Cell Wall Structure
It comprises an outer membrane and a thin peptidoglycan layer. This outer membrane comprises phospholipids and lipopolysaccharides responsible for the bacteria's antibiotic resistance. The peptidoglycan layer is composed of glycan strands cross-linked by short peptides, which provide the bacteria with strength and rigidity. Together, these components make up the Gram-negative cell wall structure. This structure enables the bacteria to survive in harsh environmental conditions and has implications for developing antibiotics that target Gram-negative bacteria.Difference Between Deoxyribose and Ribose
What is Gram Staining?
The technique of Gram staining was given by Christian Gram to find the difference between the two types of bacteria based on the difference in their structures of the cell wall. In this process, the bacteria are distinguished, found in the gram-positive bacteria's cell wall.Difference Between Darwinism and Lamarckism
Process of Gram Staining
Steps to be followed for the process of Gram staining:- Take a glass slide and smear bacteria samples from the culture on it with the help of an inoculation loop.
- Fix the bacteria on the slide to prevent it from getting washed away in the later steps. It is done by heat-fixing the glass slide over a flame.
- Add a few drops of crystal violet to the bacteria sample.
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- Add iodine molecules to the sample; it is golden brownish.
- Here, the crystal violet and iodine molecules bind together.
- Wash the bacteria with alcohol which is a de-staining chemical. In Gram-positive bacteria, the capsule of the cell gets washed away.
- In this step, we must apply safranin to the bacterial samples; safranin is a pinkish biological stain.
- Results: The results for Gram-positive vs Gram-negative bacteria will differ as mentioned above.
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Differences in Function
The gram-negative cell layer comprises multiple layers of peptidoglycan molecules, which are held together by various proteins. Gram-negative bacteria have a cell wall but are much thinner and comprise a single layer of peptidoglycan molecules. In addition, the Gram-negative cell wall has an outer membrane composed of lipopolysaccharides and lipoproteins. This outer membrane helps the bacteria to protect itself from environmental factors such as antibiotics. As a result, Gram-negative bacteria are more resistant to antibiotics than Gram-positive bacteria.Difference Between Exon and Cistron
Summary
- Gram-positive and Gram-negative bacteria are distinct types of bacteria, distinguished by their cell walls.
- Gram-positive bacteria contain a thick peptidoglycan layer in their cell walls, while Gram-negative bacteria contain a thin layer of peptidoglycan sandwiched between two other layers.
- Gram-positive bacteria are best known for their ability to resist antibiotics and are often more resistant to environmental changes than Gram-negative bacteria.
- Gram-negative have an outer membrane that makes them more susceptible to environmental stressors and antibiotics.
- Gram-positive and Gram-negative bacteria have important roles in nature, and each relative prevalence can vary in different environments.
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FAQs" accordion=1]Difference between Gram Positive and Gram Negative Cell Walls <span style=
Which bacteria are more harmful, Gram-positive or Gram-negative bacteria?
Gram-negative bacteria are more harmful as it is more resistant to antibiotics.
How can we distinguish Gram-positive and Gram-negative bacteria?
We can distinguish the two by the Gram staining method
Give a few examples of Gram-positive bacteria.
The Bacteria of Genre Staphylococcus, Enterococcus, and Streptococcus are examples of Gram-positive bacteria.
Give a few examples of Gram-negative Bacteria.
Escherichia, Salmonella etc., are examples of Gram-Negative Bacteria.
Which type of infections are caused by Gram-Positive Bacteria?
Gram-positive Bacteria cause urinary tract infections and pneumococcal infections.
Which is easier to kill, Gram-positive or Gram-negative bacteria?
Gram-positive bacteria are easy to kill because of peptidoglycan walls, whereas Gram-negative bacteria cannot be killed easily.
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