Each enzyme has an "active site". The active site of each enzyme is unique in terms of 3D structure. Each unique active site can be thought of as a 3D surface that is able to bind only a single unique substrate or set of substrates, and it is the shape of the active site that is responsible for each enzyme's substrate selectivity. Most enzymes actually use the same or nearly the same, mechanisms of action; most commonly simple acid-base chemistry is used to catalyse reactions.
It may be difficult to understand, but enzyme active sites are actually thought to bind the "transition state" of the substrate. The transition state may be thought of as a state where the structure of the substrate is literally stretched to be somewhere between the orginal substrate structure, and the structure of the product of the enzyme catalyzed reaction. In other words, the enzyme can be thought of as "pulling" the substrate into a product. In this way, the enzyme lowers the energy required to pass the "transition" state, and accelerates the reaction of substrate to product.
Thus, the structure of the enzyme imparts both its substrate specificity (because only certain substrates will fit into the active site), and its activity (because in binding the substrate, the enzyme lowers the transition energy required for the substrate to form product).
Hope this helped, despite my rambling.
Answer:
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Can you tell me what time period they are referring to?
Island hopping is one of the important military strategy against the Japanese empire at the time of World War 2.
Explanation:
Another name for Island Hopping is Leapfrogging, this strategy was used during war because the Allies used air attacks as well as submarine to isolate the bases of Japan weakening their power as well as reducing the resupply process. This strategy helped United States to reach Japan fast within a limited period of time without using large amount of manpower. So it can be said that it was a good strategy used during World War 2.
The island hopping strategy was difficult because it was a costly process but it helped America to have control over many Island present in the Pacific.
There are approximately 1500-2000 different languages spoken in Africa as well as many more dialects.