GCSE-readyEnzymes
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Enzymes are the proteins that make the chemical reactions in your body fast enough to keep you alive.
Biological catalysts
Enzymes are proteins that speed up reactions without being used up.
Each enzyme has an active site with a specific shape. Only one substrate fits, like a key in a lock.
Each enzyme has an active site with a specific shape. Only one substrate fits, like a key in a lock.
Temperature and pH
Each enzyme works best at its optimum temperature and pH.
Too hot, or the wrong pH, and the active site changes shape. The substrate no longer fits. The enzyme is denatured, and this cannot be undone.
Too hot, or the wrong pH, and the active site changes shape. The substrate no longer fits. The enzyme is denatured, and this cannot be undone.
Digestive enzymes
Carbohydrases such as amylase break starch into sugars.
Proteases break proteins into amino acids.
Lipases break lipids into fatty acids and glycerol.
Proteases break proteins into amino acids.
Lipases break lipids into fatty acids and glycerol.
An enzyme reaction makes 30 cm3 of oxygen in 60 seconds. Find the rate of reaction.
- rate = amount of product ÷ time
- rate = 30 ÷ 60
- = 0.5
Answer: 0.5 cm3/s
Enzymes are protein catalysts with a specific active site. High temperatures or the wrong pH change the active site's shape and denature the enzyme.
The interactive lesson includes the diagrams for this topic.
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