Golgi Apparatus

The Golgi apparatus, also known as the Golgi body or Golgi complex, is a type of organelle (i.e., a structure located in the cell) that processes and packages proteins and lipid molecules (i.e., fat molecules). These are later transported to other cell compartments (e.g., lysosomes or the plasma membrane) or secreted from the cell. 

When the Golgi apparatus was discovered in 1898 by Camillo Golgi, it was one of the first organelles of the cell to be discovered. He discovered it while researching the nervous system. Camillo Golgi referred to his discovery as the “internal reticular apparatus”, and it was not until 1910 that the organelle became named for him.

The Golgi apparatus is a series of stacked membranes that are located within the cytoplasm (i.e., gel-like fluid held in the cell membrane) in all eukaryotic cells (i.e., complex cells). It can typically be found adjacent to the nucleus and rough endoplasmic reticulum (an organelle involved in protein synthesis).

The function of the Golgi apparatus is processing and packaging proteins that have exited the rough endoplasmic reticulum to be further transported inside and/or outside the cell. In plant cells, the Golgi body also serves as the site for the synthesis of complex polysaccharides. 

The Golgi body contains Golgi stacks, which can be thought of as a series of trafficking pathways that work by modifying protein and other complex polysaccharides. The number of Golgi stacks a cell has largely depends on the cell type. These Golgi stacks contain anywhere from 3 to 20 flattened membrane sacs, which are called cisternae. These Golgi cisternae are usually classified based on what they import and export into the Golgi body, and each contains a different set of processing enzymes. Therefore, the Golgi cisternae are a very important part of the packaging and processing that occurs in the Golgi body. 

Transport vesicles usually pick up the molecules from the rough endoplasmic reticulum and transport them to the cis face (i.e., area of the Golgi apparatus located nearby to the endoplasmic reticulum) of the Golgi stacks, where they fuse with the Golgi membrane and are sorted based on their next destination. They are then moved through the Golgi cisternae as they undergo remodeling and other modifications. The modified protein or lipid molecules then depart from the trans face (i.e., area of the Golgi apparatus pointing towards the plasma membrane) of the Golgi stacks where they are either secreted from the cell, or transported to another cell compartment. 

The complex network of membranes and vesicles in the Golgi stacks where molecules enter are also known as the cis Golgi network.

The Golgi apparatus, also known as the Golgi body or Golgi complex, is an organelle that processes and packages proteins and lipid molecules (i.e., fat molecules) that are later exported to other cell compartments or secreted from the cell. The Golgi body has Golgi stacks, which are involved in modifying proteins and other complex polysaccharides. Transport vesicles pick up the molecules from the rough endoplasmic reticulum and transport them to the cis face of the Golgi stacks, where they fuse with the Golgi membrane and are sorted. They are then moved through the Golgi cisternae and undergo remodeling and other modifications. The modified protein or lipid molecules then depart from the trans face of the Golgi stacks where they are either secreted from the cell, or transported to another cell compartment.