Final answer:
Glucose is produced in plant cells via photosynthesis where sunlight is used to convert carbon dioxide and water into glucose. Excess glucose is stored as starch or converted to cellulose. This glucose is fundamental for the energy storage and structural components of plants.
Step-by-step explanation:
Glucose is synthesized in plant cells through the process of photosynthesis. During photosynthesis, plants convert carbon dioxide (CO₂) and water (H₂O) into glucose (C6H12O6) using energy from sunlight. The basic reaction can be represented as 6 CO₂ + 6H₂O + energy → C6H12O6 + 6O₂. The glucose thus produced serves as an energy source for the plant or can be converted into other carbohydrates such as starch or cellulose for storage or structural purposes.
The excess glucose in plants is stored as starch, a mixture of amylose and amylopectin, both of which are polymers of glucose. Starch is mainly stored in plant parts like roots and seeds and is a significant source of dietary energy for humans and animals.
On the other hand, cellulose, which is also a polymer of glucose monomers linked by β 1-4 glycosidic bonds, provides structural support to plant cell walls.
Therefore, glucose in plant cells originates from the Calvin cycle within the chloroplasts, the site of photosynthesis.