Both animal and plant cells have cell membranes that enclose the cell, are filled with cytoplasm, a gel-like substance containing chemicals needed by the cell, have a nucleus where DNA is stored, have ribosomes, protein builders of cells, have mitochondria that use oxygen to breakdown food and release energy, have vacuoles that contain food, water, or waste products, have endoplasmic reticulum, where a system of tubes transports proteins, have Golgi bodies to distribute proteins outside of the cell, and have cell walls that provide structure.