The primary source of carbohydrates for energy storage in plants is starch. Plants synthesize starch through the process of photosynthesis, converting sunlight into chemical energy stored in glucose molecules. These glucose units are then polymerized into starch, allowing plants to store energy for times of low light or limited resources. When needed, enzymes break down starch back into glucose, providing energy for growth, reproduction, and metabolic processes. This stored energy is vital not only for the plants themselves but also forms the foundation of the food web, supporting herbivores and, consequently, higher trophic levels.