BIOL 1010 Lecture Notes - Lipid Bilayer, Competitive Inhibition, Peptide

• School: Dalhousie University
• Department: Biology
• Course: BIOL 1010
• Professor: n/a

Document Summary

Some solutes pass readily through the lipid bilayer of a cell membrane, whereas others pass through much more slowly, or not at all. Small nonpolar (hydrophobic) molecules, such as dissolved gases (o2, co2, n2) and small lipids, can pass directly through the membrane. They do so by interacting directly with the hydrophobic interior of the lipid bilayer. Very small polar molecules such as water and glycerol can pass directly through the membrane, but much more slowly than small nonpolar molecules. The mechanism that permits small polar molecules to cross the hydrophobic interior of the lipid bilayer is not completely understood, but it must involve the molecules squeezing between the hydrophobic tails of the lipids that make up the bilayer. Polar molecules such as glucose and sucrose have very limited permeability. Large molecules such as proteins cannot pass through the lipid bilayer.