Golgi apparatus is a group of flattened membranous cisternae formed from vesicles that pinch off of the ER and coalesce.

• Polypeptides in the cisternae are glycosylated and otherwise modified in the Golgi complex.
• At the “maturing” face of the Golgi, new vesicles pinch off and are sorted to different destinations according to their contents.
• Most such vesicles either secrete their contents by exocytosis or remain in the cytoplasm as lysosomes or peroxisomes.
• The Golgi is generally difficult to see by LM, but examine the ultrastructural views and diagrams of this structure in Figures 2-20 through 2-23.

Describe the movement of proteins from synthesis in the rER through secretory granules about to undergo exocytosis.

Give some reasons why Golgi complexes are usually hard to see with the light microscope.

Lysosomes are next.