Do bacteria have a cell wall
Gram-Postive The phrase ‘gram-positive’ is a term used by microbiologist to classify bacteria into two groups (gram-positive or gram-negative). This positive/negative reference is based on the bacterium’s chemical and physical cell wall properties.
To determine if a bacteria is gram-positive or gram-negative a microbiologist will perform a special type of staining technique, called a Gram Stain. The name comes from its discoverer and inventor, Han Christian Gram (Gram, 1884). This stain will either stain the cells purple (for positive) or pink (for negative).
Gram-positive bacteria have a very thick cell wall made of a protein called peptidoglycan. These bacteria retain the crystal violet dye (one of the 2 main chemicals used for gram staining). Whereas, gram-negative bacteria have a very thin peptidoglycan layer that is sandwiched between an inner cell membrane and a bacterial outer membrane.
Gram-Negative Gram-negative bacteria do not retain the crystal violet stain because of its physical makeup and will stain pink. Thus, why they are called gram-negative. You also need a microscope to see this stain coloring. The microbes are still very tiny and are usually placed on a slide prior to staining.
This image is a very simple representation of how bacterium cell walls look. The protein I am talking about is in red.
The phrase ‘gram-positive’ is a term used by microbiologist to classify bacteria into two groups (gram-positive or gram-negative). This positive/negative reference is based on the bacterium’s chemical and physical cell wall properties.
To determine if a bacteria is gram-positive or gram-negative a microbiologist will perform a special type of staining technique, called a Gram Stain. The name comes from its discoverer and inventor, Han Christian Gram (Gram, 1884). This stain will either stain the cells purple (for positive) or pink (for negative).
Gram-positive bacteria have a very thick cell wall made of a protein called peptidoglycan. These bacteria retain the crystal violet dye (one of the 2 main chemicals used for gram staining). Whereas, gram-negative bacteria have a very thin peptidoglycan layer that is sandwiched between an inner cell membrane and a bacterial outer membrane.
Gram-NegativeGram-negative bacteria do not retain the crystal violet stain because of its physical makeup and will stain pink. Thus, why they are called gram-negative. You also need a microscope to see this stain coloring. The microbes are still very tiny and are usually placed on a slide prior to staining.
This image is a very simple representation of how bacterium cell walls look. The protein I am talking about is in red.
