2.1.4: Enzymes Flashcards
What are enzymes?
Biological catalysts made of globular proteins that speed up reactions without being used up themselves.
What is the active site of an enzyme?
A small part of the enzyme that attaches to a substrate to catalyse a reaction.
Why is the active site unique?
It is specific and unique in shape due to the specific folding and bonding in the tertiary structure of the protein.
What types of reactions do enzymes catalyse?
Intracellular and extracellular reactions.
Give an example of an intracellular enzyme.
Catalase, which breaks down hydrogen peroxide into oxygen and water.
Give an example of an extracellular enzyme.
Trypsin, which hydrolyses proteins in the small intestines.
What is activation energy?
The amount of energy required before a reaction can occur.
How do enzymes affect activation energy?
They lower the activation energy needed for the reaction to occur.
What is the Lock and Key Model Hypothesis?
A model suggesting the enzyme is like a lock and the substrate is like a key that fits into it due to the enzyme’s specific tertiary structure.
What is formed when an enzyme and substrate attach?
An enzyme-substrate complex.
What happens to the substrate when it binds to the enzyme’s active site?
It is distorted, which lowers the activation energy.
What is created after the substrate reacts with the enzyme?
An enzyme-product complex.
True or False: Enzymes can be reused after catalysing a reaction.
True.
Fill in the blank: Enzymes are ________ that speed up biochemical reactions.
biological catalysts
What is the role of the charged groups within the active site?
They are thought to distort the substrate and lower the activation energy.
In which part of the cell is catalase found?
Inside liver cells.
Where does trypsin function?
In the small intestines.
