Organelle of eukaryotic cells involved in transportation and modification of proteins, targeted to the plasma membrane or to the space outside the plasma membrane.

The golgi apparatus is a stack formed of several parallel membrane cisternae (see figure). Proteins are transported to the golgi apparatus from the endoplasmatic reticulum by small membrane vesicles. Similar vesicles are transporting proteins within the stack from one cisterna to the other. During their stay in the golgi apparatus, proteins are partially modified (for example by linking them to various carbohydrates).