BIOL 1090 Lecture Notes - Lecture 14: Lipid Raft, Facilitated Diffusion, Active Transport
10 Apr 2018
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Document Summary
Amphipathic phospholipids are main structural components of biological membranes. Cells with different functions have different membrane compositions. Integral proteins have transmembrane domains that are embedded in membranes. In response to changes in temperature, lipid composition of membranes can be changed by. If added to a liquid crystal membrane, fluidity will decrease. If added to a crystalline gel membrane, fluidity will increase. Lipid rafts are small areas of plasma membrane that are enriched in certain types of lipids. Lipid bilayers do not allow many compounds to pass through them freely. Large/polar/charged compounds can not easily cross lipid bilayers. Specific mechanisms exist for the controlled transport of many substances across membranes. Change in transporter conformation allows compound to be released on the other side of the membrane. Ion channels are formed by integral membrane proteins that line an aqueous pore. Selective channels, allowing only a certain type to pass. Channel responds to changes in charge across membrane.
