Catalysts and Enzymes
Catalysts speed reactions without being consumed.
About this topic
A catalyst speeds up a reaction by providing an alternative pathway with lower activation energy, without being consumed. It does not change the overall energy change or the position of equilibrium; it only helps the reaction reach equilibrium faster. Enzymes are biological catalysts, mostly proteins, that are highly specific to their substrates.
A catalyst lets more collisions have enough energy to react. Homogeneous catalysts are in the same phase as the reactants, while heterogeneous ones, such as solid platinum for gas reactions, offer a surface where reactants adsorb and react. Enzymes bind a substrate at the active site in a lock-and-key or induced-fit way, lowering the barrier. Their activity depends on temperature and pH: too hot or the wrong pH denatures them and the shape is lost. Inhibitors can block them.
Examples: manganese dioxide makes hydrogen peroxide bubble faster, catalytic converters in cars convert carbon monoxide and nitrogen oxides to less harmful gases, iron is used in the Haber process, and amylase in your saliva breaks starch into sugar. Catalase in liver and potato rapidly decomposes hydrogen peroxide into oxygen and water. Industry uses catalysts to save energy and cost.
A misconception is that catalysts are used up or that they add energy; they are regenerated and only lower the barrier. They speed up forward and reverse reactions equally.
Key ideas
- Lower activation energy
- Enzymes are biological catalysts
- Catalytic converters clean exhaust
Quick check
Use cases: where Catalysts and Enzymes helps
- Homework: review the key idea behind Catalysts and Enzymes before you start a problem set.
- Exam revision: use the quick check to test whether you can recall Catalysts and Enzymes without notes.
- Visual learning: play with the interactive lab to see how Catalysts and Enzymes changes when you adjust its inputs.
- Teaching a friend: explain Catalysts and Enzymes in your own words, then compare your version with the key ideas.
Chemistry explains medicine, food, cleaning products, fuels and building materials.
Frequently asked questions
What is Catalysts and Enzymes?
Catalysts speed reactions without being consumed.
What will I learn in Catalysts and Enzymes?
Lower activation energy. Enzymes are biological catalysts. Catalytic converters clean exhaust.
Is Catalysts and Enzymes part of Chemistry?
Yes. It is one of 150 Chemistry topics on LearnViz HighSchoolEdu, with 3 key ideas, a live animation and a quick check.
Does the Catalysts and Enzymes lab work on a phone or tablet?
Yes. The animation resizes to fit your screen and supports touch, so you can drag, tap and slide with your finger.
How should I study Catalysts and Enzymes?
Read the summary and key ideas first, play with the interactive lab to see the idea in motion, then answer the quick check. If you get a question wrong, go back to the key idea it tests.
Do I need an account, and is my progress saved?
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