What is catalyst in Science?
A catalyst is a substance that increases the rate of a reaction by decreasing the activation energy (energy required to start the reaction). It does so by creating a new reaction mechanism (the way the reaction happens on a molecular level) that happens more easily and with less energy. For example, a catalyst could attract both reactants, thus bringing them directly together and facilitating the reaction.
A catalyst is a substance that aids a chemical reaction (by doing this increasing the reaction rate) but is not consumed by the reaction. For example, hydrogen peroxide (H2O2) spontaneously decomposes into water and oxygen over time. the addition of manganese dioxide will greatly increase the rate of reaction, but none is consumed.
not all catalyst are enzymes. There are biological catalysts as well as non biological ones catalysts are something that speeds up the rate of a chemical reaction without itself getting altered after it. for example an enzyme is a catalyst because it speed up the rate of food digestion (by breaking down food molecules) and doesn't get altered after the reaction.
Like everyone told you, catalysts increases the rate of reaction without being consumed. An easy example to think of is mixing natural gas with air --(CH4 + O2). The minute you mix them they are reacting , releasing CO2 as a byproduct and H2O. But they are reacting very slow. But take a match to that slow reaction and it instantaneously reacts with an explosion. In this case the match was the catalyst. It sped up the reaction without adding anything to the reaction or being consumed
