BIOL 102 Chapter Notes - Chapter 7: Exocytosis, Endocytosis, Active Transport
5 Oct 2018
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Document Summary
Phospholipids are free to move within the bilayer. Most lipids a(cid:374)d so(cid:373)e protei(cid:374)s (cid:272)a(cid:374)"t drift laterally. Length of fatty acyl tails, presence of double bonds in the tails, and presence of cholesterol affect viscosity of membrane. Transmembrane protein- spans the entirety of the cell membrane (integral) Peripheral membrane protein- attach to integral membrane proteins. Lipid-anchored protein- attach to hydrophilic head of phospholipid bilayer. Glycocalyx- sugar coating on membrane that helps in protection and recognition. Polar molecules and charged polar molecules and macromolecules have very low permeability in the membrane. Small uncharged molecules pass easily through membrane. Passing of molecules from high to low concentration across a permeable membrane to create equilibrium. Facilitated diffusion- passive transport (high to low concentration) with the help of a protein channel: gate can open/close from ligand, regulatory protein, phosphorylation (adding phosphate group), change in voltage, or sound waves.
