Enzymes: How Do They Work? NOTES

What are Enzymes? https://www.youtube.com/watch?v=XTUm-75-PL4 Enzymes are proteins that speed up chemical reactions in your body. Another name for an enzyme is a catalyst, a molecule that speeds up a chemical reaction.

How do I identify an enzyme? Enzymes usually end in the suffix “–ase” Protease- Breaks down proteins found in meat, eggs, cheese, etc.! Lactase- Breaks down lactose! Lipase- Breaks down lipids!

How do enzymes speed up reactions? Enzymes speed up biochemical reactions in your body by lowering the activation energy of reactions that would normally happen (but at a much slower rate) Activation energy is the energy needed to start a reaction.

Which hill would you rather roll a boulder up? OR

How Do I Make Sense of This? Think of lowering activation energy like rolling a boulder up a hill. What takes less energy? Rolling a boulder up a high steep hill or rolling a boulder up a small hill? Rolling up a smaller hill takes less energy & time!

Components of Enzyme Reactions A substrate is the material the enzyme works on (example: lactose) The active site is the pocket or groove in the enzyme where the reaction happens (think of it like the mouth of the enzyme) The enzyme remains unchanged during and after the reaction

PRODUCT SUBSTRATE ACTIVE SITE ENZYME

The Lock and Key Model Enzymes and substrates fit together like a lock and key! Only one type of key can open a lock. In the same way, only ONE type of enzyme can work with ONE type of substrate. Ex: Lactose <3 Lactase (Soul mates)

How Do Enzymes and Substrates Pair Up? Enzymes bind substrates into its active site (pocket or groove) While the enzyme and the substrate are joined, the enzyme catalyzes (speeds up) the reaction. The enzyme converts the substrate into something new (breaks the substrate up or adds something) to form the PRODUCT. The enzyme DOES NOT CHANGE and can be used again!

One more picture…

Check for Understanding 1. What do we call the model that represents how enzymes and substrates fit together? Why do we call it that? The lock and key model because only 1 enzyme works for 1 substrate. 2. What happens to the enzyme after a chemical reaction? What happens to the substrate? The enzyme stays the same and can be used again. The substrate is converted to a product after it is broken apart or something is added.