|
|
Article: Bacterial Membranes and Cellwall
- Article from:
- World of Microbiology and Immunology
CopyrightCOPYRIGHT 2003 The Gale Group Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
|
Bacterial membranes and cell wall
Bacteria
are bounded by a cell wall. The cell wall defines the shape of the microorganism, exerts some control as to what enters and exits the bacterium, and, in the case of infectious
microorganisms
, can participate in the disease process.
Many bacteria can be classified as either Gram-positive or Gram-negative. The Gram stain is a method that differentiates bacteria based on the structure of their cell wall. Gram-positive bacteria retain the crystal violet stain that is applied to the bacteria, and appear purple. In contrast, gram-negative bacteria do not retain this stain, but are "counterstained" red by the safranin stain that is applied later. ...