Plants primarily store energy in the form of starch. Starch is a polysaccharide made up of numerous glucose units linked together. During photosynthesis, plants convert sunlight into chemical energy, which they use to produce glucose from carbon dioxide and water.
Once synthesized, glucose can be used immediately for energy or converted into starch for storage. This storage occurs mainly in roots, tubers, seeds, and some fruits, allowing plants to have a reserve of energy that can be utilized during times when sunlight is limited, such as during the night or in the winter.
The choice of starch as a storage form is advantageous because it is less soluble in water compared to glucose, which helps maintain osmotic balance within plant cells. When energy is needed, plants can break down starch back into glucose through a process called hydrolysis.