5: Enzymes Flashcards
What is a catalyst?
A substance that increases the rate of a chemical reaction and is not changed by the reaction (or not used up)
What is an enzyme?
A protein that is involved in all metabolic reactions, where they function as biological catalysts
Why are enzymes important in all living organisms?
They allow reactions to occur at the correct speed necessary to sustain life.
Explain enzyme action in reference to: active site, enzyme-substrate complex, substrate and product
Enzymes are specific in their action, meaning they only work on the right substrate. The active site is the part of the enzyme that fits together with the substrate. This is referred to as the lock and key model. When the substrate collides with the correct active site, it forms an enzyme-substrate complex. This reaction reacts quickly to form the products. After the products are released, the enzyme is left unchanged and is ready to catalyse another reaction.
What is an anabolic reaction?
A reaction that builds bigger molecules
What is a catabolic reaction?
A reaction that breaks down molecules
How does temperature affect enzyme activity?
Enzymes increase their rate of reaction with an increase in temperature, however, enzymes have an optimum working temperature, beyond which they are denatured. As temperature increases, the particles gain kinetic energy so the particles move faster and this increases the chances of an enzyme-substrate complex forming.
How does pH affect enzyme activity?
Changing the pH will alter the rate of reaction because the shape of the active site is distorted.
