Question

What is the cell wall made out of?

Answer 1

Hint: A cell wall is a structural layer that surrounds some types of cells just outside the cell membrane. It can be tough, flexible, and even rigid at times. It provides structural support and protection to the cell while also acting as a filtering mechanism. Cell walls are present in most prokaryotes (except mollicute bacteria), algae, fungi, and eukaryotes, including plants, but are absent in animals.

Complete answer:
The most significant distinction between plant and animal cells is that plant cells have a cell wall as well as a cell membrane, whereas animal cells only have a cell membrane. In plants, bacteria, fungi, and algae, the cell wall is located outside of the cell membrane. It's a tough, rigid layer that gives the cell structural support and protection.

Many plant cells have a primary cell wall that supports the cell as it grows, as well as a secondary cell wall that develops inside the primary wall after the cell has stopped growing. Secondary cell walls are much thicker and stronger than primary cell walls, and they make up the majority of wood.

Plant cell walls are primarily composed of cellulose, the most abundant macromolecule on the planet. Cellulose fibers are long, straight polymers made up of hundreds of glucose molecules. The cell wall of plant cells surrounds the plasma membrane and provides tensile strength as well as resistance to mechanical and osmotic stress. It also enables cells to develop turgor pressure, which is the pressure of the cell contents against the cell wall.

Note: The cell wall in most cells is flexible, meaning it will bend rather than hold a fixed shape, but it has significant tensile strength. The apparent rigidity of primary plant tissues is enabled by cell walls, but it is not due to the stiffness of the walls. This rigidity, as well as the wall structure, is created by hydraulic turgor pressure.