The golgi apparatus is an important cell organelle for processing proteins synthesized by the rough endoplasmic reticulum (RER). In structure, a golgi body resembles a stack of dishes or shallow bowls. A cell may have many golgi bodies, and a golgi body has many sacs, The structure of the golgi organelle is polar with two faces or aspects that differ in form and functions. One aspect, or face of the golgi is closer to the rough endoplasmic reticulum. This side is the convex side of the sacs ; it is also known as the cis or entrance face. The concave aspect of the golgi faces the plasma membrane; this is called the trans or exit face. The cis face of the gogi body receives proteins from the RER and passes then into the medial cisternae for further elaboration. The trans side of the golgi has cisternae that pass out properly modified and labelled proteins to their assigned destinations.
Work Step by Step
Proteins made by RER enter the golgi at the cis face, and then move into the medial cisternae, Here they are modified by enzymes, Carbohydrates, lipids, or phosphate groups may be added to different molecules to form glycoproteins, lipoproteins and glycolipids, The modified proteins move through the medial cisternae to the cisternae of the trans end. Here the molecules are further modified , packaged, and assigned for transport to three destinations; 1. Some proteins in vesicles are transported to the plasma membrane where they are utilized in repairing or extending the plasma membrane. 2. Some vesicles containing enzymes or hormones are transported to the plasma membrane for export: these vesicles fuse with the plasma membrane and release their contents into the extracellular fluid by exocytosis. Insulin, for example, for example, may be released by pancreatic cells by this mechanism. 3. Some proteins are packaged in vesicle to be used in cell organelles. This is the case of the digestive enzymes of lysosomes