ABSTRACT
This chapter considers the molecular mechanisms of budding and fusion that underlie all vesicular transport. It discusses the fundamental problem of how, in the face of this transport, the cell maintains the differences between the compartments. The chapter also considers the function of the Golgi apparatus, lysosomes, secretory vesicles, and endosomes, as we trace the pathways that connect these organelles. In plant cells, the Golgi apparatus is generally more distinct and more clearly separated from other intracellular membranes than in animal cells. Lysosomes are membrane-enclosed compartments filled with soluble hydrolytic enzymes that control intracellular digestion of macromolecules. Like all other intracellular organelles, the lysosome not only contains a unique collection of enzymes, but also has a unique surrounding membrane. Lysosomes are usually meeting places where several streams of intracellular traffic converge. Lysosomes are specialized for the intracellular digestion of macromolecules. Recycling endosomes can serve as an intracellular pool of specialized plasma membrane proteins that can be mobilized when needed.
