The Golgi apparatus

At some point in their lives all cells need to grow and divide. In eukaryotic cells these processes require the delivery of new proteins and lipids from their site of synthesis in the endoplasmic reticulum (ER) to the cell surface. The Golgi apparatus, first visualised under the light microscope in 1898 by Camillo Golgi using a staining method he had developed to study neurons, lies on the route between the ER and other destinations within the cell. The electron microscopic (EM) studies of Felix and Dalton in the 1950s revealed that the Golgi apparatus is comprised of a series of overlapping cisternal or plate-like, membrane structures and associated 60 to 70 nm diameter vesicles. Palade and co-workers then went on to demonstrate from their studies of pancreatic cells that secreted proteins pass through the Golgi apparatus on their way to the cell surface or other destinations within the cell such as the lysosomes. This layered cisternal structure is often called a stack, and has a defined polarity, cisbeing the face accepting material from the ER, and transbeing the face where material exits for secretion.