Plants use sugar for energy at night and as the building blocks for growth. Plants are able to store sugar in different forms, including maltose, sucrose, fructose and glucose. They can convert sugar into starches.
Plants use photosynthesis to make sugar, which serves as an energy source, and is used to help plant growth. This process occurs only during the daytime, as plants need sunlight to carry out photosynthesis. Excess sugar produced is stored in the plant until needed, such as at night or during the winter. During those times when the plant is unable to use photosynthesis for energy, those sugar stores help keep the plant healthy and allow it to continue growing.
Plants also convert sugar into starch, which is a core component of plant cell walls. These starchy walls surround the plants photosynthetic cells, serving as protection and structural support. Starch is made up of chains of sugar molecules, sometimes thousands of these molecules. There are some plants that have more starch than others, and usually these are plants that have tubers like potatoes, but also include rice and wheat. These plants can also break down their starches for fuel when needed. Starches provide a large amount of energy because they are made up of so many simple sugar molecules.