Enzymes Flashcards
What are enzymes?
Large proteins that catalyse reactions. They are not changed in the reactions that they catalyse.
What is an enzyme’s active site?
The place where the reaction occurs
What is the substrate?
The piece that fits into the enzyme - the “key”
What is the “lock”?
The enzyme
Why do enzymes only catalyse specific reactions?
Each substrate is specific to the enzyme.
What do enzymes do to molecules in a reaction?
Active site - enzymes either:
1. Break down molecules into smaller ones
2. Bind small molecules together into larger ones
What happens when the products have been released in a reaction?
Enzyme’s active site can accept another substrate molecule
What effect does temperature have on enzymes?
As temperature increases, rate of reaction increases.
When the temperature is too hot, enzymes denature.
Why does the rate of reaction increase as temperature increases? (enzyme reaction)
The enzyme and substrate molecules have more kinetic energy so vibrate more -> collide more frequently
What 2 factors can denature an enzyme?
- Extremes of pH
- High temperatures
Why can denatured reactions no longer catalyse a reaction?
The active site has changed shape, so the substrate can no longer bind
What do digestive enzymes do?
Convert food into small, soluble molecules that can be absorbed into the blood
What reaction does amylase catalyse?
Starch -> glucose
Where is amylase produced/secreted?
Salivary glands, pancreas, small intestine
What reaction does protease catalyse?
Proteins -> amino acids
Where is protease produced/secreted?
Stomach, pancreas, small intestine
What reaction does lipase catalyse?
Lipids -> fatty acids and glycerol
Where is lipase produced/secreted?
Pancreas, small intestine
How are enzymes adapted to work well in different environments?
Different enzymes have different optimum pH levels.
