Behind the Scion xB, the Civic, in coupe and sedan form, is the second most reliable compact car. Both versions start under $19,000, and benefit from two consecutive years of updates. After a lackluster 2012 model, Honda went back to the drawing board, and then again provided updates for 2014.
A catalyst is a chemical that increases the rate of a chemical reaction without itself being changed by the reaction. The fact that they aren't changed by participating in a reaction distinguishes catalysts from substrates, which are the reactants on which catalysts work. Enzymes catalyze biochemical reactions. They are similar to other chemical catalysts in many ways: Enzymes and chemical catalysts both affect the rate but not the equilibrium constant of a chemical reaction. Reactions proceed downhill energetically, in accord with the Second Law of Thermodynamics.
The role of the enzyme is to reduce the activation energy, by bringing specific molecules together, rather than relying on random collisions) Action on specific Substrates. Enzymes are substrate specific, meaning only one particular substrate molecule can work with one particular enzyme. This is due to the reciprocally shaped active site. Since the enzyme is never chemically alter by a reaction, it can be reused in subsequent reactions â enzyme controlled reactions are always reversible.