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quasi426 is offline
Nov27-06, 11:40 PM
P: 208
Also remember the size of bacteria and the cost benefits of seeing with vision. Many of the bacteria's inputs of the outside environement are through channels and receptors that lead to signal transduction cascades. That is to say that some outside stimulus can bind on a transmembrane protein known as receptors on the outer surface of the bacteria, the receptor will cause internal chemical reactions that lead to more internal chemical reactions that will finally lead to a change in concentration of a messenger molecule. The messenger molecule's concentration can control DNA expression which can lead to metabolic changes that may be required such as degrading a toxin, or internalizing and metabolizing energy source.