Q.Describe the three layers that together make up the cell envelope of a typical bacterial cell, naming them from outermost to innermost.

[!TLDR]

The bacterial cell envelope's three layers, outermost to innermost, are: glycocalyx, cell wall, and plasma membrane.

[!ANSWER]

Glycocalyx (outermost) -> cell wall (middle) -> plasma membrane (innermost).

The bacterial cell envelope is made up of three distinct layers working as a single protective unit. The outermost layer is the glycocalyx, built mainly of polysaccharides, which may form a thick, well-organised capsule, a loose slime layer, or a minimally developed layer, depending on the species. The middle layer is the cell wall, chiefly responsible for the cell's shape and its resistance to osmotic bursting, built in most bacteria from the polymer peptidoglycan. The innermost layer is the plasma membrane, the selectively permeable boundary chemically similar in basic organisation to the plasma membrane of a eukaryotic cell.

[!ANSWER]

Glycocalyx (outermost) -> cell wall (middle) -> plasma membrane (innermost).

List the three layers in the correct outside-to-inside order, naming the main chemical component of each.

Reversing the order (placing the plasma membrane outermost) or omitting the glycocalyx as a distinct outermost layer separate from the cell wall.