C5.2.2 Enzymes as Biological Catalysts

• Enzymes are highly specific, meaning they only catalyze reactions involving particular substrates
• What do enzymes lower in order to speed up reactions?

  Activation energy
• Match the enzyme-substrate interaction model with its description:

  Lock and Key ↔️ Enzyme has a fixed shape

  Induced Fit ↔️ Enzyme changes shape
• What two main models describe the enzyme-substrate interaction?

  Lock and Key, Induced Fit
• The Lock and Key Model assumes that enzymes are flexible and can change shape to fit the substrate.

  False
• What does the specificity of enzymes allow them to do?

  Bind and catalyze reactions
• Match the characteristic of enzymes with its description:

  Specificity ↔️ Catalyze only certain reactions

  Biological catalysts ↔️ Found in living organisms

  Lower activation energy ↔️ Speeds up reaction rates
• Enzymes, like non-biological catalysts, lower activation energy to speed up reactions.


  True
• Enzymes function best at any pH level.

  False
• Deviations from optimal pH can alter the enzyme's active site shape
• What prevents a denatured enzyme from catalyzing reactions?

  Loss of 3D shape
• Cellulase is used in the food industry to break down proteins.

  False
• What are enzymes defined as in biology?

  Biological catalysts
• Enzymes are found in living organisms, while non-biological catalysts are found in chemical processes.


  True
• Non-biological catalysts are less specific than biological enzymes
• The induced fit model assumes enzymes can change shape to accommodate substrates.


  True
• The enzyme-substrate interaction describes how enzymes bind to and catalyze reactions with their specific substrates
• Arrange the steps in the enzyme-substrate interaction according to the Induced Fit Model.

  1️⃣ Enzyme's active site changes shape

  2️⃣ Substrate binds to the active site

  3️⃣ Enzyme catalyzes the reaction

  4️⃣ Products are released
• Enzymes function best at specific pH
• What do enzymes lower to speed up chemical reactions?

  Activation energy
• Enzymes are highly specific because they only catalyze reactions involving particular substrates
• Arrange the effects of temperature on enzyme activity from lowest to highest.

  1️⃣ Enzyme activity increases with temperature

  2️⃣ Enzyme activity reaches its optimal point

  3️⃣ Enzyme denatures and activity decreases
• What happens to enzyme activity when all active sites are occupied by substrates?

  Enzyme saturation
• Denaturation of an enzyme causes it to lose its 3D structure and become inactive.


  True
• Match the industry with the enzyme and its application:

  Food ↔️ Amylase - Breaks down starches

  Textiles ↔️ Cellulase - Softens fabrics

  Pharmaceuticals ↔️ Proteases - Aid in drug synthesis