BIOL 1090 Lecture Notes - Lecture 17: Lipid Bilayer, Biological Membrane, Amphiphile
18 Jan 2017
School
Department
Course
Professor
Document Summary
Organelle: membrane bound compartment with characteristic content and a specific function. Separate section/part of something, considered to be in isolation. Compartmentalizes: divides a whole into separate parts/sections. Formed from the boundary and the contents. Example is a biological membrane: phospholipid bilayer made of phosphorus and a fatty acid chain in 2 layers: amphipathic: has both non-polar (hydrophobic) and polar (hydrophilic) regions, biological membranes contain a hydrated lipid bilayer. Nature if lipids in membrane: unsaturated increase fluidity, saturated reduces fluidity. Temperature: warming increases fluidity (liquid crystal, cooling decreases fluidity (crystalline gel) A balance between order and disorder provides: support and flexibility, dynamic interactions between membrane components, membrane assembly and modification. Cholesterol regulates fluidity: alters packing and flexibility of lipids, if added to liquid crystal membrane fluidity will decrease, if added to crystalline gel fluidity will increase. Mosaic: diverse molecules penetrate the lipid bilayer. Model by singer/nicolson, 1972: bilayer of amphipathic lipids, proteins: Peripheral: proteins attach to a lipid in the bilayer.
