According to the University of Cincinnati, the starch in a potato cell reacts with iodine to show an outline of the cell's organelles, particularly the nucleus. Iodine leaves a purplish impression on the starch grains, allowing easy identification.
Staining is a common practice within microbiology and other sciences. Within examination of a stained cell culture, it is important not to be misled by the presence of air bubbles, as they can mimic the appearance of organelles to the untrained eye. Organelles are structures found within the cell. Each organelle has its own purpose and function. The nucleus, specific to eukaryotic organisms, is host to the cell's DNA and chromosomes. Organelles native to both plant and animal cells include the nucleus, vacuole and Golgi apparatus, among many others. The vacuole is responsible for storage, primarily that of water and certain enzymes. Meanwhile, the Golgi apparatus processes proteins. A key difference between animal cells and plant cells like those of the potato is their respective method of energy production. Animal cells contain organelles called mitochondria, which produce energy through respiration. Plant cells contain chloroplasts, which produce energy through photosynthesis. Additionally, plant cells feature a hard cell wall, while animal cells contain a softer cell membrane.