EVERYDAY SCIENCE

Detailed explanation-1: -The peptidoglycan (murein) sacculus is a unique and essential structural element in the cell wall of most bacteria. Made of glycan strands cross-linked by short peptides, the sacculus forms a closed, bag-shaped structure surrounding the cytoplasmic membrane.

Detailed explanation-2: -The Gram-positive cell wall has a very thick peptidoglycan layer, which holds the crystal violet dye during the Gram staining procedure. The thick layer of peptidoglycan lies above the cell membrane.

Detailed explanation-3: -The crystal violet dye adheres to the thick peptidoglycan layer of the cell wall present in gram-positive bacteria, staining them violet or purple when visualized under a light microscope.

Detailed explanation-4: -The peptidoglycan wall (PG) is a unique structure which confers physical strength and defined shape to bacteria. It consists of a net-like macromolecule of peptide interlinked glycan chains overlying the cell membrane.

Detailed explanation-5: -The thickened peptidoglycan layer in Gram positive cells allows them to retain the stain (hence remaining ‘stain positive’ or ‘Gram positive) where as the thin layer seen in Gram negative cells cannot prevent the stain from leeching out (hence stain and Gram negative).