Golgi Apparatus- Definition, Structure, Functions and Diagram


The Golgi apparatus is one of the most fascinating and important organelles in eukaryotic cells. It is responsible for processing, sorting and delivering proteins and lipids to various destinations inside and outside the cell. It also plays a role in synthesizing carbohydrates, proteoglycans and other molecules that are essential for the structure and function of the cell.

The Golgi apparatus was named after its discoverer, Camillo Golgi, who observed it in 1898 using a staining technique that he developed. He described it as a "black reticulum" that was present in many types of cells. However, his findings were controversial and not widely accepted until the 1950s, when electron microscopy revealed the true structure and complexity of the Golgi apparatus.

The Golgi apparatus consists of a series of flattened membrane-bound sacs called cisternae, which are arranged in stacks called dictyosomes. The number and size of the stacks vary depending on the cell type and function. The cisternae are connected by tubules and vesicles that transport materials between them. The Golgi apparatus has two distinct faces: the cis-face, which faces the endoplasmic reticulum (ER) and receives newly synthesized proteins and lipids from it; and the trans-face, which faces the plasma membrane and releases modified proteins and lipids to their final destinations.

The Golgi apparatus performs different functions depending on the type of molecule that passes through it. Some molecules are modified by adding or removing sugar groups (glycosylation), phosphate groups (phosphorylation), sulfate groups (sulfation) or other chemical groups. Some molecules are sorted and packaged into different types of vesicles that bud off from the Golgi apparatus. Some molecules are transported to other organelles such as lysosomes, peroxisomes or mitochondria. Some molecules are secreted out of the cell by exocytosis.

The Golgi apparatus is essential for many cellular processes such as cell growth, differentiation, signaling, immunity, development and disease. It is also involved in the formation of some cellular structures such as the cell wall in plants, the acrosome in sperm cells and the cortical granules in egg cells. The Golgi apparatus is highly dynamic and responsive to changes in the cellular environment and demands. It can undergo structural and functional changes such as fusion, fission, fragmentation, relocation or degradation.

In this article, we will explore the definition, structure, functions and diagram of the Golgi apparatus in more detail. We will also discuss some of the discoveries and advances that have been made in understanding this remarkable organelle..