Unit 13 Golgi Apparatus PDF

10/10/2023 Unit 13: The Golgi apparatus Unit 13: The Golgi apparatus Discovery...

10/10/2023 Unit 13: The Golgi apparatus Unit 13: The Golgi apparatus Discovery Camillo Golgi discovered this organelle under LM in 1898 ‐ Discovery He called it internal reticular apparatus In 1914 Cajal showed the relation to secretory activity ‐ Morphology and structure Around 1950: First electron micrograph ‐ Localization in the cell ‐ Polarity and compartments ‐ Functions LM Drawing made by Golgi Purkinje cells in cerebellum. Method: Golgi impregnation Cell Biology and Histology Cell Biology and Histology Unit 13: The Golgi apparatus Unit 13: The Golgi apparatus In 1914 was related to secretory activity First electron micrograph (around 1950) Morphology and structure Consists of a network of smooth membranous flattened cisternae, vesicles, tubules and vacuoles. Frequently located near the nucleus. Frequently arranged in a slightly curve stack Drawings made by Cajal Cell Biology and Histology Cell Biology and Histology  10/10/2023 Unit 13: The Golgi apparatus Unit 13: The Golgi apparatus Morphology and structure Cisternae Vesicles Dictyosome Tubules Vacuoles The number of dictyosomes /cell is variable depending on the cell type. Example: Around 50 dictyosomes in the hepatocyte. See Figure 14A in Atlas de ultraestructura celular. See Figure 14A in Atlas de ultraestructura celular Cell Biology and Histology Cell Biology and Histology Unit 13: The Golgi apparatus Unit 13: The Golgi apparatus Localization in the cell: Examples Localization in the cell Golgi apparatus is present in all cells except erythrocytes Perinuclear………………………….. Neuron granules Supranuclear………………………… Secretory cells (i.e. goblet cell) Near the nucleus………………….. Plasma cell At both sides of the nucleus….... Muscular fibers, fibroblasts Throughout the cytoplasm……… Hepatocyte, plant cells Goblet cell A good exercise would be to make an schematic drawing of these cell types Cell Biology and Histology Cell Biology and Histology  10/10/2023 Unit 13: The Golgi apparatus Unit 13: The Golgi apparatus Polarity and compartments Polarity and compartments The Golgi apparatus has two distinct morphological and functional faces Functions And 5 compartments CIS face (formation) 1 2 3 4 5 Man: Mannose TRANS face GlcNAc: N‐Acetylglucosamine (maturation) Gal: Galactose NANA: Sialic acid Cell Biology and Histology Cell Biology and Histology Unit 13: The Golgi apparatus Unit 13: The Golgi apparatus Functions 1. Modification of proteins and lipids Golgins: Filamentous proteins ₋ Glycosylation of the Golgi matrix that capture transport vesicles ₋ Proteolysis ₋ Sulfation 2. Sorting and distribution of the different macromolecules ₋ To plasma membrane (recycling of membranes) ₋ To lysosomes ₋ To secretory vesicles Particular examples: ₋ Formation of acrosome (is a special lysosome in sperm cells) ₋ Formation of the plant cell wall Cell Biology and Histology Cell Biology and Histology  10/10/2023 Unit 13: The Golgi apparatus Unit 13: The Golgi apparatus We saw this slide in Unit 7: Sorting in the TGN (in a secretory cell) Macrotransport/Exocytosis................... Glycosylation Sorting, packaging and distribution of the Proteins (from RER) Proteolysis different macromolecules in vesicles and Lipids (from SER) Sulfation granules Cell Biology and Histology Cell Biology and Histology