arrive. After leaving secretory vesicle the proteins to the plasma membrane or lysosomes. A specific oligiosacchride block is transferred to new many proteins inserted into the ER during translation. The Golgi apparatus is going to further process the oligiosacchrides.Carbohydrates liked to new proteins in the ER, some carbohydrates linked to new proteins after processing in the Golgi.Specific cisternae have specific roles. A key function is oligiosacchride processing trimming and addition of other sugar monomers, Human genome encodes hundreds of different glycoslytranserase enzymes.Addition of different types of sugars, and trimming until only mannose sugars are exposed no addition.Why glycosylation? Increase solubility of hydrophobic folding intermediates, prevents aggregation, cell surface is covered with glycoproteins oligiosacchrides limit protease access to surface proteins=protective coating without rigidity of cell wall. Oligosaccharides recognized by receptors called lectins immunity, development, cell-cell communication and adhesion.Delivery of newly synthesized proteins and membrane from the Golgi to lysosomes. Certain proteins and membrane must be replaced back to the Golgi.Lysosomes digest macromolecules and lipids, enriched in hydrolyctic enzymes. What prevents self-digestion? Hydrolyctic enzymes are activated by, proteolytic cleavage of inactivating sequence amino acid sequence (zymogens) acidic environment. Therefore hydrolases are inactive if leaked into cytosol. V-ATPase pump acidifies lysosomal lumen. There are vesicle traffic routes that converge on lysosomes, they are the biosynthetic pathway, endocytosis pathway, the phagocytosis pathway, and autophagocytosis pathway.The machinery of degradation (all the destructive enzymes). Large molecules can be sent to the lysosome so as to break them down into building blocks that the cell can then use for other uses.What makes lysosome easily recognized is the Mannose 6-phosophate side chain. Only happens to proteins that are being lysed, it is a mark that things that are being sent to the lysosome.Mannose 6-phosphate receptor binds this tag to allow packaging into the vesicles in Golgi. The mannose 6-phospahte is incorporated into a vesicle. The receptors are used deliver lysosomal proteins from the Golgi to late endosome/lysosome. Dissociation the phosphate group falls off and the vesicle is delivered. Mannose 6-phosphate is packaged and returned so it can be used in transportation again.Exocytosis: delivering membranes from the Golgi to the plasma membrane and beyond. If not soluble it will be secreted to other parts of the body. **Slide 46** There is both constitutive and regulated secretory pathway. Membrane depolarization or intracellular Ca2+ allows for allows for triggered regulation of the excretion of the cell and its fluids.