Catalysts

• Catalysts change the rate of chemical reactions but are not used up during the reaction.
• Different reactions need different catalysts.
• Enzymes act as catalysts in biological systems.
• Catalysts increase the rate of reaction by providing a different pathway for the reaction that has a lower activation energy.
• Activation energy - the minimum amount of energy that colliding particles must have for them to react
• Product - a substance formed in a chemical reaction
• Catalyst - a substance that changes the rate of a chemical reaction without being changed by the reaction itself
• Enzyme - a protein which catalyses or speeds up a chemical reaction
• Reactant - a substance that reacts together with another substance to form products during a chemical reaction
• Reaction pathway - the sequence of reactions needed to produce a desired product from a particular set of raw materials
• Catalysts do not change the frequency of collisions.
• A catalyst provides an alternative reaction pathway that has a lower activation energy. This means that more particles have enough energy to react.
• Catalysts are not shown in word or symbol equations.
• Enzymes are biological catalysts, they are proteins that speed up chemical reactions in cells.
• Different reactions need different catalysts. Not all reactions have suitable catalysts.
• Only a very small mass of catalyst is needed to increase the rate of a reaction.
• A catalyst is not chemically changed or used up at the end of the reaction.
• A catalyst is a substance that increases the rate of a reaction.
• A catalyst does not alter the products of the reaction.