Final answer:
In plant cells, vacuoles store sugar, while mitochondria break down sugar to release energy.
Step-by-step explanation:
In plant cells, vacuoles store sugar molecules. These vacuoles are membrane-bound organelles that can hold various substances, including sugars. On the other hand, mitochondria are responsible for breaking down sugar, such as glucose, to release energy in the form of ATP (adenosine triphosphate). During cellular respiration, glucose oxidation occurs which releases a considerable amount of free energy, sufficient to synthesize many ATP molecules. The glycolysis pathway is the initial step in the breakdown of glucose, taking place in the cytoplasm, and is a part of the metabolic pathway both in prokaryotic and eukaryotic cells. Post glycolysis, further reactions occur within the mitochondria that lead to even more production of ATP. This process is called cellular respiration. Mitochondria are known as the powerhouse of the cell because they produce the majority of the cell's energy.