Biology 1002B Lecture Notes - Lecture 7: Active Transport
Document Summary
Lec 7 membrane biology y membranes are made up of lipid bilayer: it has hydrophilic head and hydrophobic tail y. It is amphipathic both hydrophilic and hydrophobic parts. Importance of unsaturation y fatty-acid structures affect the fluidity of the membrane y more unsaturated membrane = more fluid (less viscous) Membrane permeability y diffuse through membrane: hydrophobic molecules (o2, co2, n2, small, uncharged polar molecules (h20, glycerol) y cannot diffuse, large, uncharged polar molecules (glucose, sucrose) Ions (cl-, k+, na+) y molecules that can t diffuse use membrane proteins y how can proteins interact with hydrophobic core: alpha helix minimizes charge of backbone, non-polar amino acids in hydrophobic regions (core of membrane) Transmembrane protein prediction y given the primary sequence of a protein, can you predict whether it spans a membrane: yes. Look for regions where concentration of non-polar amino acids is high => this region spans the membrane.