Enzymes Flashcards
What is an enzyme?
A protein that speeds up the rate of chemical reactions
What is the active site of an enzyme?
Where the substrate molecules bind to
What type of structure do enzymes have?
Tertiary structure
What is the activation energy of a chemical reaction?
The amount of energy required to start the reaction.
How do enzymes affect the activation energy?
Lowers activation energy. (Speeds up rate of reaction)
What is the model used to describe enzyme action?
The ‘induced fit’ model
What determines the shape of the active site on an enzyme?
The tertiary structure of the enzyme
What factors can change the tertiary structure of an enzyme?
pH and temperature.
What are the two ways to measure enzyme activity?
How fast the product is made and how fast the substrate is broken down
What happens when you increase the temperature of an enzyme - controlled reaction?
Reaction speeds up due to more kinetic energy, so the substrate is more likely to collide with the enzymes’ active site.
What happens if the temperature gets 100 high in an enzyme-controlled reaction?
The reaction stops because the enzymes are denatured.
What does it mean if an enzyme is denatured?
The enzymes’ active site has changed shape so the substrate no longer fits.
What happens if an enzyme is above or below its optimum pH?
It denatures
Why do enzymes denature if they’re not at their optimum pH?
Hydrogen bonds in enzymes’ tertiary structure break so active site shape changes.
What happens in an enzyme-controlled reaction if you increase the substrate concentration?
The rate of reaction is faster because there is more of a chance of a collision between an enzyme and a substrate.
