Lesson 4 - Enzymes Flashcards
What is an enzyme?
An enzyme is a biological catalyst that speeds up chemical reactions in the body without being used up.
What does the “lock and key” theory describe?
The “lock and key” theory explains how enzymes work. The enzyme’s active site (the lock) is specific to the substrate (the key) it acts on, meaning only the correct substrate can fit.
What is a substrate?
A substrate is the molecule that an enzyme acts upon. It binds to the enzyme’s active site during a chemical reaction.
What is the active site of an enzyme?
The active site is the specific part of the enzyme where the substrate binds and the reaction takes place.
What happens to the substrate when it binds to the enzyme’s active site?
The enzyme helps break down or build up the substrate into the products of the reaction, after which the enzyme is ready to be reused.
Why are enzymes specific to certain reactions?
Enzymes are specific because their active sites have a unique shape that only fits a particular substrate, like a key fits a specific lock.
What factors can affect enzyme activity?
Enzyme activity can be affected by:
Temperature: Too high or low can denature the enzyme.
pH: Extremes of pH can also denature the enzyme.
What does it mean for an enzyme to be denatured?
Denaturation happens when an enzyme loses its shape, so the active site no longer fits the substrate. This can be caused by high temperatures or extreme pH levels.
