Original presentation by M.Bregar (Dante C.S.S.Face extracellular fluid and serve as “cell identifiers”.Serve as recognition sites for chemicals.GLYCOPROTEINS found on the surface of the membrane.electrostatic or ionic interactions with membrane lipids (e.g.through a calcium ion) interaction by a covalently bound membrane lipid (lipidation) 4. interaction by an amphipathicα-helix parallel to the membrane plane (in-plane membrane helix) 2. Predominately interact with integral proteins.Functions: serve as ion channels, membrane pumps, or receptors.Proteins surrounded by phospholipids which go through the membrane.PHOSPHATE HEAD – HYDROPHYLIC FATTY ACID TAILS – HYDROPHOBIC PHOSPHOLIPID ORIENTATION PHOSPHATE HEADS – are water loving and point toward water FATTY ACID TAILS – are water fearing and orient themselves to each other Liposome is a small vesicle, with an aqueous compartment surrounded by a bilayer.In water, phospholipids form a bilayer.Phospholipids are like triglycerides with a phosphate.Protective barrier - contains cytoplasm (contents of the cell)įUNCTIONS OF PLASMA MEMBRANE Transport Regulates movement of substances in / out of cell (selectively permeable)įUNCTIONS OF PLASMA MEMBRANE Cell recognition Allows cells to identify surrounding cells įUNCTIONS OF PLASMA MEMBRANE Cellular Attachment Cell membranes have junctions – surfaces which interlock keeps cells together – and surfaces which attach them to the extra cellular matrix.įUNCTIONS OF PLASMA MEMBRANE Signal Transduction converts a mechanical/chemical stimulus to a cell into a specific cellular response.įUNCTIONS OF PLASMA MEMBRANE Enzyme Activity Cells rely on thousands of different enzymes to catalyze metabolic reactions, many of these occur at the cell membrane.Ion Channel Ions have charges (positive or negative) and.
molecules move from high to low with the help of plasma proteins (b) Facilitated diffusion. Passive Transport: (a) Simple Diffusion molecules move from high to low between phospholipid molecules. Model says cell membrane is not solid, fluid. Passive Transport - requires NO cell energy.Model describing structure of the cell membrane.\): In an aqueous solution, phospholipids tend to arrange themselves with their polar heads facing outward and their hydrophobic tails facing inward.
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