Final answer:
The Golgi apparatus is a cell organelle that processes proteins and lipids, packages them into vesicles, and distributes them within the cell or outside of it.
Step-by-step explanation:
The Golgi apparatus is a crucial cell organelle involved in protein processing and lipid transport. Discovered by Camillo Golgi in 1898, the Golgi apparatus appears as a series of stacked, membrane-bound discs known as cisternae. Its primary functions include modifying, sorting, and packaging proteins and lipids for secretion outside the cell or for use within the cell. This process is akin to a post office, packaging and labeling items before sending them to their destinations within the cell. The Golgi apparatus is particularly important in cells with high secretory demands, such as antibody-secreting plasma cells. In addition to proteins, it also processes lipids by attaching sugar molecules to them, creating glycoproteins and glycolipids which are essential for the plasma membrane and for cell-to-cell communication.
In plant cells, the Golgi apparatus also synthesizes polysaccharides used in the cell wall or elsewhere within the cell. It is closely associated with the endoplasmic reticulum (ER), where it receives newly synthesized proteins housed in transport vesicles. These vesicles then fuse with the Golgi's cisternae, where proteins undergo further modifications, including the addition of oligosaccharide chains.