key term - Gram-positive cells

Definition

Gram-positive cells have thick peptidoglycan layers in their cell walls, which retain the crystal violet stain used in the Gram staining procedure. These cells appear purple under a microscope after the staining process.

5 Must Know Facts For Your Next Test

1. Gram-positive bacteria have a thicker peptidoglycan layer compared to Gram-negative bacteria.
2. They lack an outer membrane, which is present in Gram-negative bacteria.
3. Teichoic acids are commonly found within the cell wall of Gram-positive bacteria and play roles in cell wall maintenance and ion transport.
4. The Gram staining method differentiates bacteria into Gram-positive (purple) and Gram-negative (pink/red) based on their cell wall composition.
5. Some well-known Gram-positive bacteria include Staphylococcus aureus and Streptococcus pyogenes.

Review Questions

Related terms

Peptidoglycan:

A polymer that forms a protective layer around bacterial cells.

Teichoic Acids:

Polymers found within the cell wall of Gram-positive bacteria that contribute to its rigidity.

Gram Staining:

A common laboratory technique used to differentiate bacterial species into two groups based on their cell wall properties.