Final answer:
Carbohydrates, specifically cellulose, are the primary source of energy and the main structural component of plant cell walls. Cellulose is comprised of long chains of glucose and is abundant in the plant kingdom, providing dietary fiber and raw materials for various industries.
Step-by-step explanation:
The primary source of energy for plant cells and the structural component of plant cell walls is carbohydrates. Plants produce carbohydrates through the process of photosynthesis, as represented by the chemical equation 6 CO₂ + 6H₂O + 686 kcal → C6H12O6 + 6O2, where the energy in the form of 686 kcal comes from solar energy. Specifically, the monosaccharide glucose can be utilized by plants for immediate energy or can be converted into larger carbohydrate molecules like starch, for energy storage, and cellulose, for structural support.
Cellulose is a polysaccharide that makes up the plant cell wall and is the most abundant carbohydrate. It is formed by long chains of glucose units, which provide the rigidity and strength necessary for the plant structure. Unlike starch, which is used for energy storage, cellulose serves as the primary structural component. Moreover, the abundance of cellulose in plant cell walls makes it a significant component of dietary fiber for humans, as well as a vital raw material for paper and textile production.