CAIE A Level Biology 9700 · Cell membranes and transport
Describe the fluid mosaic model of cell surface membrane structure and the ordered stages of cell signalling from the secretion of a signalling molecule to the response in a target cell. In your answer, you should refer to the roles of phospholipids, cholesterol, glycolipids, glycoproteins, and proteins (including receptor, channel, and carrier proteins).
5 marks, so the mark scheme is looking for about 5 separate creditworthy points. Making the same point twice in different words earns it once.
Describe means: Say what happens or what something is like, in order and with detail. You are not being asked why. If there is data, quote it: name the trend, then give figures with units at the points where it changes.
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