Unit 2 - Module 1 - Enzymes Flashcards
What does the enzyme lactase break down?
The milk sugar, lactose, into glucose and galactose monomers.
How are enzymes similar?
All globular proteins Act as catalysts Specific Have an active site Activity is affected by temperature and pH.
What does then enzyme catalase break down?
Hydrogen peroxide into water and oxygen gas.
What are extracellular enzymes?
They catalyse reactions outside the cell.
For example mould produces them to digest bread.
What are intracellular enzymes?
They catalyse reactions inside the cell.
What is the lock and key model?
The shape of the active site is complementary to the substrate, like a lock and key. The substrate is held in place so the reaction can go ahead.
What is the induced fit hypothesis?
As substrate collides with active site, the enzyme changes shape slightly. This makes active site fit more closely. It fits because oppositely charged groups found near each other
The change in enzyme shape places a strain on substrate molecule, which destabilises it so the reaction occurs more easily.
Products formed are a different shape and no longer fit in active site so move away.
What is the effect when the temperature is first increased on an enzymes?
It increases the amount of kinetic energy, which increases the number of collision between enzymes and substrates. Therefore rate of reaction increases.
