Topic 2 - lipid bilayer (lec 3)

2 once the membranes are in place they are very

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Unformatted text preview: rane. 2) Once the membranes are in place they are very useful as an organizational tool . They can be used to organize enzymes for biochemical activities. BIO 1140 – SLIDE 2 3. Regulation of solute transport 4. Responses to external signals 5. In and out of cell and/or organelles Uphill or downhill e.g. Na+,K+-ATPase Receptors and signal transduction e.g. ß-adrenoreceptor Cell-to-cell communication Recognition, adhesion, exchange of materials Gap junctions, plasmodesmata Fig. 7-2, Becker et al. 2009 BIO 1140 – SLIDE 3 3) Membranes are also responsable for controlling solute movement in and out of the cell or in and out of organelles. Transport proteins in the membrane control the movements of solute across that membrane. Think about the sodium pump for example. The sodium potassium ATPase 4) The membrane also the first point of contact in the cell and its environment. so the membrane contains receptors protein receptors that allow it to respond to environmental signals. The response takes the form of detecting the signal and turing it into a cellular response, so both detection of the signal and signal trasnduction, that is turning that signal into a cellular response. This is the second major fuction of the membrane 5) In a multicellular organism, the membrane is a important spot for recongizing other cells in the environment. so if cells are going to be linked together, that linking occurs in the membrane. The membranes have to recongize each other and form some kind of attachment. They may also be an important site of exchange of material b/w the cells, in both animal and plant cells u find communicating juctions. Its a point were the cells exchange info directly form one cytoplasm to another though these membrane structures. Plasma membrane of Schwann cell (myelin sheath) 18% protein 82% lipid Inner mitochondrial membrane 76% protein 24% lipid BIO 1140 – SLIDE 4 Figs. 6.8, 36.5 > In the fluid mosaic model u have a double layer of lipids that are held together by non-colvalent interactions, so they are highly fluid. There are no c...
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This note was uploaded on 02/19/2014 for the course BIO 1140 taught by Professor Fenwick during the Winter '07 term at University of Ottawa.

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