A bacterial cell is a microorganism that may be pathogenic or nonpathogenic. Bacterial cells come in a variety of shapes and sizes, such as rod shaped, spherical, curved, square shaped and star shaped.
Bacterial cells may be gram positive or gram negative. Both types of bacterial cells have cell walls, but these have different compositions. Gram positive bacterial cells contain thick peptidoglycan walls that contain high concentrations of peptides. Gram negative bacterial walls contain thin peptidoglycan walls and exhibit enzymes that help them with mobility. Gram negative bacteria also contain lipid A, which is an endotoxin that can protect the bacterial cell.