YEAR 9 Enzymes Flashcards
Define an enzyme
A protein which acts as a biological catalyst
How to tell apart a sugar and enzyme from NAME
Ose SUGAR
Ase ENZYME
What is lock and key theory for enzymes
Only one specific substrate fits an enzyme’s active site
Explain the induced fit theory
The active site approximately fits the substrate and flexes to fit perfectly once bonded
Define a substrate for enzymes
The molecule that is changed in a reaction
Why do extreme pH denatured enzymes
Ions break bonds in the enzyme, changing the shape of the active site
Why does very high temperature denature enzymes
Molecules gain kinetic energy
Vibrations break bonds and denature enzyme
Define a denatured enzyme
An enzyme which has permanently changed shape due to broken bonds between amino acids
What is catalase
enzyme which quickly breaks down hydrogen peroxide into water and oxygen
What is the Benedict’s test
SUGARS
Mix tested substance with solution in hot water bath
Red = Lot
Blue = Little
What is the Biurets test
PROTEINS
Add tested substance to solution and mix
Purple = Lot
Blue = Little
What is the ethanol emulsion test
LIPIDS AND FATS
Mix tested substance with ethanol and add water
Drops of fat and lipids will separate + float to top
Why does a higher temperature increase rate of reaction with enzymes
More kinetic energy
More frequent collisions with enzymes and substrates
What does amylase catalyse
Starch into sugars
Can a cold temperature DENATURE an enzyme
No
It will only slow the rate of reaction
