AP BIOLOGY

Detailed explanation-1: -No, bacterial cells lack a cell membrane. Instead of a cell membrane, they contain the cell envelope, which is an outer membrane of prokaryotic cells.

Detailed explanation-2: -The cell membrane is surrounded by a cell wall in all bacteria except one group, the Mollicutes, which includes pathogens such as the mycoplasmas. The composition of the cell wall varies among species and is an important character for identifying and classifying bacteria.

Detailed explanation-3: -Gram-negative and mycobacteria have an inner and outer bacteria membrane. As a phospholipid bilayer, the lipid portion of the bacterial outer membrane is impermeable to charged molecules.

Detailed explanation-4: -Bacteria have a well-defined cell wall composed of peptidoglycan. It protects the bacteria from outer environment and can also confer pathogenicity. Gram-negative bacteria have two layers of cell walls, one inner peptidoglycan layer, and one outer lipopolysaccharide layer.