BIOL 1090 Lecture Notes - Lecture 3: Active Transport, Epithelium, Integral

• School: University of Guelph
• Department: Biology
• Course: BIOL 1090
• Professor: Andrew Bendall

Document Summary

Structure of biological membranes: all membranes share common properties, 6nm thick (with associated water), stable, flexible and capable of self assembly (ex. Liposomes: membranes have different functions in different cells and within an individual cell, different areas of the plasma membrane perform different functions (ex. Cholesterol: rafts are relatively rigid, some membrane proteins accumulate in rafts, may for(cid:373) (cid:858)fu(cid:374)(cid:272)tio(cid:374)al (cid:272)o(cid:373)part(cid:373)e(cid:374)t(cid:859) Lipid raft within a membrane: simple diffusion, very small molecules, uncharged, down a (cid:272)o(cid:374)(cid:272)e(cid:374)tratio(cid:374) gradie(cid:374)t (cid:894)flow is (cid:858)dow(cid:374)hill(cid:895, ex. Ions move down the concentration gradient: often channels are (cid:858)gated(cid:859) (can be opened or closed, 3 types of gated channels, voltage gated channels (ex. K+ channel: channel responds to changes in charge across membrane, ligand-gated channels (ex. Acetylcholine: cha(cid:374)(cid:374)el respo(cid:374)ds to (cid:271)i(cid:374)di(cid:374)g of spe(cid:272)ifi(cid:272) (cid:373)ole(cid:272)ule (cid:894)a (cid:858)liga(cid:374)d(cid:859)(cid:895, mechano-gated channels (ex. Cation channels in inner ear: channel responds to physical force on membrane (ex.