BIO 1140 Lecture Notes - Lecture 7: Electron Microscope, Clathrin, Microfilament

• School: University of Ottawa
• Department: Biology
• Course: BIO 1140
• Professor: Caroline Petit- Turcotte

Document Summary

Lec 7 : membranes and transport (feb 2) Diffusion of molecules from one compartment to the other. Driving force of diffusion : increase in entropy. Initial state : molecules are more concentrated in one region/side of membrane (energy more localized) As diffusion occurs : entropy increases as the energy spreads out until molecules are evenly distributed (highest entropy) As distribution proceeds max disorder : molecules release free energy, can accomplish work (free energy = work) Equilibrium : same concentration inside and outside cell , molecules move at equal rates in both directions. Depends on concentration difference (concentration gradient) between two areas/across membrane. Larger gradient = faster rate of diffusion. Equilibrium : same concentration inside and outside cell , molecules move at equal rates in both directions, but no change in concentration. Movement of small substances through the lipid part of a biological membrane. Rate depends on : molecular size and lipid solubility.