BIOL 230W Lecture Notes - Lecture 37: Vesicle Fusion, Cell Membrane, Exocytosis
Document Summary
Biol 230w lecture 37 membrane transporters. Conformational changes of snares binding help trigger fusion. Requires hydrolysis of gtp via rab g-protein. Researchers are unsure about how fusion works: hypothesize that conformation changes create favorable energetics for fusion. Rab gtp hydrolysis results in rab dissociation with membrane. Constitutive (unregulated) vs. regulated: calcium plays a role in regulated, fusion requires energy. Similar to other vesicle fusion events: requires snare proteins. Toxins destroy vsnares before complex formation inhibition of neurotransmitter exocytosis. Very few molecules can simply diffuse through the lipid bilayer: small, non-charged (nonpolar) Transporters are integral membrane proteins used for transport. Passive transport: use kinetic energy and diffusion to transport molecules down a concentration gradient. Active transport: uses light, atp, or electrochemical gradient to transport molecules up a concentration gradient. Passive transport: no energy required, rely on diffusion, simple diffusion. Protein provides a tunnel for a specific molecule. Gated channels: channels only open based on certain conditions.
