Cells of Bacteria and Archaea
What is a key difference between the cell wall compositions of Archaea and Bacteria?
A. Archaea contain a membrane-bound nucleus; bacteria do not.
B. DNA is present in the mitochondria of both bacteria and archaea.
C. Archaea contain small membrane-enclosed organelles; bacteria do not.
D. DNA is present in both archaea and bacteria.
Answer:
Archaea and Bacteria have different cell wall compositions and plasma membrane lipids.
Typical cells in Archaea and Bacteria contain a cell wall, cell membrane, nucleoid region, and often a capsule, flagellum, and pili. However, these structures are sometimes made from different chemical compounds.
The key difference lies in the cell wall composition. The cell walls of Bacteria contain peptidoglycan, which provides strength and rigidity to the cell wall. On the other hand, Archaea do not have peptidoglycan in their cell walls.
Moreover, the plasma membrane lipids of Bacteria consist of fatty acids, while those of Archaea are made up of phytanyl groups. This distinction in cell wall composition and plasma membrane lipids is one of the defining features that differentiate Archaea from Bacteria at a cellular level.
In summary, while both Archaea and Bacteria share certain cellular structures, such as a cell wall and cell membrane, the composition of these structures sets them apart from each other.