Christian René de Duve (1917- present) was awarded one-third of the 1974 Nobel Prize in Physiology and Medicine for his discoveries concerning the structural and functional organization of the cell. Using fellow Nobel Prize winner Albert Claude's technique of separating the components of cells by spinning them in a centrifuge, he discovered that cells damaged in the process released acid phosphatase in proportion to the amount of damage done. He showed that acid phosphatase was enclosed within the cell in a membranous envelope that formed a self-contained organelle. He named the organelle "lysosome" and identified it by using an electron microscope. The discovery of the lysosome explains how enzymes used by cells to digest nutrients are kept separate from other cell components.