1 At the post office (USPS.com), a money order that is from $0.01 to $500 can cost $1.15, while a money order for $500 to $1,000 will cost $1.55. Single money orders will have a maximum limit that is usually around $1,000. 2  So if you had to purchase $1,500 worth of money orders, you would have to purchase two separate money orders, which means you will have to pay for each one. 3  International money orders can cost $3 to $6.
Enzyme catalysis is the increase in the rate of a chemical reaction by the active site of a protein. The protein catalyst (enzyme) may be part of a multi-subunit complex, and/or may transiently or permanently associate with a Cofactor (e.g. adenosine triphosphate).Catalysis of biochemical reactions in the cell is vital due to the very low reaction rates of the uncatalysed reactions.A key driver of protein evolution is the optimization of such catalytic activities via protein dynamics. The mechanism of enzyme catalysis is similar in principle to other types of chemical catalysis.By providing an alternative reaction route the enzyme reduces the energy required to reach the highest energy transition state of the reaction.ovalent catalysis involves the substrate forming a transient covalent bond with residues in the enzyme active site or with a cofactor. This adds an additional covalent intermediate to the reaction, and helps to reduce the energy of later transition states of the reaction.
Catalysts and activation energy To increase the rate of a reaction you need to increase the number of successful collisions. One possible way of doing this is to provide an alternative way for the reaction to happen which has a lower activation energy. In other words, to move the activation energy on the graph like this: Adding a catalyst has exactly this effect on activation energy. A catalyst provides an alternative route for the reaction.