Biochemistry 2288A Lecture Notes - Lecture 8: Phospholipid, Amphiphile, Hydrogen Bond
17 Jun 2016
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Document Summary
The membranes are not just lipids, there are a lot of proteins there that are doing things. There"s a lot more lipids but they"re smaller in mass, therefore they"re equal. Implication: membranes are not just passive barriers to polar molecules! A lot of things are charged/polar, and wont want to go through the membrane. You have to use a protein (most of the time) to get them across. Required to move ions and polar molecules from one side to the other. Transporters: speci c binding site, conformational changes during transport. Channels: open pathway, discriminating based on size and charge a. Facilitated transports are helping things pass through using a protein. It is favourable for them to go from the outside to the inside. Active: molecule moves against electrochemical gradient; use a source of energy. Electrochemical gradient: when molecules diffuse from large to small or from more positive (or more negative) to less positive (or less negative)
