Question

describe active site structure

Answer 1

Active Site structure is what allows an enzyme and its substrate to interact. If the substrate cant fit into the active site on the enzyme then the enzyme cannot do the work it needs to do. Also, if active sites didnt differ then any substrate could attatch to the enzyme and then the enzyme would not be doing its job. Each enzyme has a specific substrate that will fit into its active site. There are other things such as competitive inhibition and noncompetitive inhibition of the active site. These come into play when enough substrate has been acted on by the enzyme and the enzyme needs to stop working. Competitive inhibition essentially blocks the active site and doesnt allow the enzyme to uptake anymore substrate. It can do this because it is of similar shape to the actual substrate and can sort of fit into the Active Site. Noncompetitive inhibition works differently to accomplish the same task as competitive inhibition. In noncompetitive inhibition the inhibitor molecule attatches to a remote site on the enzyme that isnt the Active Site. When this happens the inhibitor changes the shape of the Active Site and does not allow the enzyme to take in any more substrate because the two do not fit anymore. Thats about as good as I can explain it.