LIFE SCIENCE

Detailed explanation-1: -Gram-negative bacteria are surrounded by a thin peptidoglycan cell wall, which itself is surrounded by an outer membrane containing lipopolysaccharide. Gram-positive bacteria lack an outer membrane but are surrounded by layers of peptidoglycan many times thicker than is found in the Gram-negatives.

Detailed explanation-2: -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.

Detailed explanation-3: -The bacterial cytoplasmic membrane is composed of roughly equal proportions of lipids and proteins. The main lipid components are phospholipids, which vary in acyl chain length, saturation, and branching and carry head groups that vary in size and charge.