What is the main structural carbohydrate that makes up plant cell walls?

Cellulose is the main structural carbohydrate found in plant cell walls. It is a long chain polymer made up of glucose molecules linked together by β(1→4) glycosidic bonds. This structure provides rigidity and strength to plant cells, allowing them to maintain their shape and prevent collapsing under pressure. The presence of cellulose is a key factor in the overall structural integrity of plants.

This carbohydrate is abundant in nature and forms the primary component of the cell walls in many plants, contributing to their ability to withstand environmental stresses. Unlike starch, which serves as an energy storage molecule in plants, and glycogen, which is more suited for energy storage in animals, cellulose is specifically adapted for structural purposes. Sucrose, on the other hand, is a sugar used for energy transport rather than structural integrity. Hence, cellulose is the correct answer as it fulfills the role of providing support and protection to plant cells.