BIOL 101 Lecture Notes - Lecture 3: Cystic Fibrosis, Passive Transport, Glycocalyx
Document Summary
4 main components: phospholipid bilayer, cholesterol, proteins, glycocalyx. Phospholipid bilayer hydrophilic heads outward, hydrophobic tails inward. Cholesterol help maintain fluidity, cell recognition. Glycocalyx sugar chains attached to proteins and phospholipids [binding sites, lubrication, adhesion] Keep small molecules from moving through membrane. Faulty membranes can cause disease : cystic fibrosis. Glycocalyx: glycoprotein polysaccharide, cell recognition, cell-cell communication, adhesion. Membrane surfaces have a fingerprint that identifies the cell: wrong fingerprint. Attacked by immune defenses: organ transplants. Disease transmission depends on making it past the cell membrane. Concentration gradient: difference in solute concentration: move down concentration gradient. Big difference no difference: moving against concentration gradient. Passive transport: spontaneous diffusion across membrane: two types of passive transport. Facilitated diffusion: transport protein carrier, molecules can"t get thru. Osmosis (passive transport: passive diffusion of water across a membrane. Tonicity osmotic pressure: hypertonic [high solute outside of cell, water flows out, hypotonic [high solute inside cell, water flows in, isotonic [same solute in/out cell, water flows equal]
