All living organisms are formed from units called cells. All cells contain DNA to create other cells. The cells are semipermeable, which means they allow some substances to get through the membrane and deny others access. Plant cells are a bit more complex. They have internal sub-sections known as organelles and micro-fibers that form a cytoskeleton in a nucleus bound to the membrane which contains DNA. Unused sugars in plants are stored as starch. Starch is considered to be a complex sugar.

The cell wall of a plant has a barrier that the membrane presses against and that it uses to maintain a rigid structure. Inside of the plant, excess sugar is stored as starch. Starches are recognized as a major component of foods ingested into the human body, to be used as energy or stored as fat. Likewise, the plant uses these starches as stored food sources. In woody plant stems, starch is also stored for later use as energy. Trees are known to create sugar through photosynthesis; the unused sugar is transported through the phloem, stored in the trunk or roots as starch and then turned back into sugar to be used as energy again at the start of a new spring.

The glucose units in plants are linked in linear bonds. Whenever plants need energy for cell work, they hydrolyze the stored starch, releasing the glucose subunits. The strategically branched polymer of glucose used in this process is known as amylopectin; it and amylose make up the two main components of starch. Starch itself is made of at least 70% amylopectin, constituting the bulk of the plant being used for energy storage.