Biology 1202B Lecture Notes - Lecture 2: Membrane Transport Protein, Transmembrane Protein, Integral Membrane Protein
25 Jan 2017
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Endocytosis: reverse of exocytosis plasma membrane infolds creating a vesicle, pinching off and bringing things inside the cell, cells bring in macromolecules too large for transmembrane import, pinocytosis vacuole created around extracellular fluid. (cid:862)cell dri(cid:374)ki(cid:374)g(cid:863: receptor mediated endocytosis transmembrane proteins recognize target molecules. Acquire bulk quantities of a specific molecule. Binding leads to pocket formation requires energy. Membranes and cell signalling: one of the characteristics of life is its ability to respond to change in the environment, at the cellular level this means perceiving and reacting to a signal. Directly from the environment in single celled organisms. From the environment or from other cells in multi-cellular organisms: extracellular signal needs to turn into an intracellular response. Signal to response: receptor specific for signal molecule: extracellular signal -> intracellular response. Surface receptors: transmembrane (integral) protein, extracellular signal binding domain. Binding causes a conformational change in protein. Transmission of a signal through the plasma membrane.
