BIOL 3070 Lecture Notes - Lecture 4: Osmosis, Oncotic Pressure, Lipid Raft
Document Summary
Bulk endocytosis: activity dependent exocytosis (happens when activity of cell increases rapidly. Exocytosis 2 types: intracellular vesicles fuse with membrane and release contents into extracellular space, transient occurs with release of peptide hormones at synapses for example. Typical of many classical neurotransmitters (ne, e, ach, serotonin, dopamine) Membrane-bound vesicles with contents recruited to the inner surface of plasma membrane and forms an indentation called a fusion pore (number of proteins that help release of contents into extracellular space) Transient because lasts for short period of time (70-200ms) Entire vesicle fuses with memb. and transporter/receptor proteins are inserted into membrane itself (eg. if ligand binds to receptor, ligand-receptor complex internalized via rec. med. Clathrin proteins needed for exocytosis are also recycled. Epithelial transport paracellular movement of solutes between adjacent cells: most epithelial cells have polarity (distinct apical and basal surfaces, between adjacent epithelial cells, have tight junction proteins that prevent, different types of pumps/transporter proteins depending on cell/tissue type.
