Part 02 · Moving materials, enzymes and energy · Card 4 of 11
Enzyme
A protein that speeds up a chemical reaction without being used up. Each enzyme fits one type of reaction.
Last updated
Analogy
A key that fits only one lock.
In practice
Amylase in your saliva breaks starch into sugars.
Practice
Flashcards
- Why does a denatured enzyme stop working?Its shape has changed, so the substrate no longer fits the active site.
Interview questions
- Describe how temperature affects the rate of an enzyme-controlled reaction.
- Rate rises as temperature rises because particles collide more
- There is an optimum temperature where the rate is highest
- Above the optimum the enzyme denatures
- A denatured enzyme loses its shape and cannot work
Questions people ask
What is the active site of an enzyme?
The active site is a small dent in the enzyme's surface with a precise shape. Only the matching substrate, the molecule being changed, fits into it, like a key in a lock. The enzyme then helps the reaction happen, releases the products and is ready to be used again.
Why are enzymes called biological catalysts?
A catalyst speeds up a reaction without being used up. Enzymes are made by living cells, so they are biological catalysts. Without them, reactions like digesting food would be far too slow to keep us alive. Each enzyme usually speeds up only one kind of reaction.