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).
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Answer: D) The Black Arts Movement
Explanation: The Black Arts Movement was the name given to a group of politically motivated black poets, artists, dramatists, musicians, and writers who emerged in the wake of the Black Power Movement which began in 1965 and ended in 1975.
Its C / militarism in nations of Europe!
One of the main reasons Rome did not expand farther north was because this area was inhabited by several hostile tribes and groups, that became too much of a headache for the Romans.
Explanation:
Cant be A because On May 13, 1846 the United States Congress passed An Act providing for the Prosecution of the existing War between the United States and the Republic of Mexico
Can't be B because Mexico did declared a defensive war against the U.S. on April 23, 1846.It would defend territories under the attack but would not take the offensive.
Can't be C because On April 25, 1846, a 2,000-strong Mexican cavalry detachment attacked a 70-man U.S. patrol that had been sent into the contested territory north of the Rio Grande and south of the Nueces River. In the Thornton Affair, the Mexican cavalry routed the patrol, killing 16 American soldiers.
Is D because can't find any information on this and the rest are true.
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