BIOL 021 Lecture Notes - Lecture 5: Digestion, Homeostasis, Nuclear Pore
Document Summary
Allows chemical reactions to occur without damaging us. Monitor what comes in and out of cell. Some break down nutrients while other build up. Lipid bilayer, arrangement of phospholipid (polar head hydrophilic and nonpolar tails hydrophobic) Cholesterol dispersed in non-polar fatty acid tails to keep movement. Diffusion: movement of solutes from high to low. Osmosis: movement of water from high to low. Water moves across membrane to equalize solute concentration. Equal solutes on inside and outside of the cell. Solute concentration is higher inside the cell than outside the cell. Cell will gain water to the internal environment. More solutes outside the cell than inside the cell. Cell will lose water to the external environment. Process of spontaneous passive transport of molecules or ions across a biological membrane via specific transmembrane integral proteins. Using a vesicle by merging with phospholipid bilayer. Work together to guide the cell to maintain homeostasis.
