BIOL 2021 Lecture Notes - Lecture 19: Vesicle Fusion, Lipid Bilayer Fusion, Cell Membrane
Document Summary
Red arrows: biosynthetic-secretory pathway: new proteins, carbohydrates, lipids, pm or extracellular. Green arrows: endocytosis: plasma membrane gets removed and delivered to endosomes. Blue arrows: retrieval pathways recycling: molecules get returned and reused, export things and then import them back, membrane proteins, receptors. Things get transported in membrane-enclosed transport vesicles. Cargo: anything carried inside a vesicle: soluble molecules, proteins, etc. All topologically equivalent because they don"t have to directly cross any membranes. Donor vesicle undergoes budding and the target vesicle undergoes fusion. The cargo stays in the lumen or membrane. Q: both vesicle budding from the donor compartment and vesicle fusion with the target require membrane fusion events. Fusion with target requires fusion on the cytoplasmic side. Identity: market molecules that are on the cytosolic surface. Coated vesicle: cage of proteins on the cytosolic surface. Inner coat layer (just outside the membrane: concentrates specific proteins in a patch of the membrane while forming the vesicle, outer coat layer, shapes the vesicle.