Enzymes

• What is the primary structure of a protein?

  Sequence of amino acids
• What is a peptide bond?

  A bond formed between amino acids during a condensation reaction
• What are the main functions of enzymes?

  • Speed up reactions by lowering activation energy
  • Act as biological catalysts
  • Can catalyze both catabolic and anabolic reactions
• What is the optimum temperature for enzyme activity?

  40°C
• What happens to enzymes at temperatures above their optimum?

  They denature, changing the shape of the active site
• What is the lock and key theory in enzyme action?

  It describes how the substrate fits perfectly into the active site of the enzyme
• How does the induced fit model differ from the lock and key theory?

  The active site changes shape to fit the substrate, which is not a perfect match
• What are the two types of reactions catalyzed by enzymes?

  Catabolic and anabolic reactions
• What is the role of amylase?

  It catalyzes the conversion of carbohydrates into sugars
• What is the role of protease?

  It catalyzes the breakdown of proteins into amino acids
• What is the role of lipase?

  It catalyzes the breakdown of lipids into fatty acids and glycerol
• What are the key terms related to enzyme structure and function?

  • Active site
  • Catalyst
  • Lock and key
  • Substrate
  • Activation energy
  • Induced fit
  • Specific
  • Product
• What is metabolism?

  The combination of anabolic and catabolic reactions
• What is specificity in enzyme action?

  Enzymes can only catalyze specific reactions
• What is a cofactor?

  A substance that helps enzymes work by attracting substrates
• What is the Biuret test used for?

  To test for the presence of proteins
• What color change indicates a positive result in the Biuret test?

  Blue to purple
• What happens to enzymes when they are digested?

  They are broken down by other enzymes or acids
• How does the induced fit model explain the formation of the enzyme-substrate complex?

  The active site changes shape to tightly bind the substrate, lowering activation energy
• What are the steps involved in the breakdown of a substrate by an enzyme?

  1. Substrate enters active site
  2. Induced fit changes the shape of the active site
  3. Enzyme-substrate complex forms
  4. Activation energy is lowered
  5. Bonds in the substrate are stressed and broken
  6. Products are released as they no longer fit the active site
• What is the role of the active site in an enzyme?

  It has a specific 3D shape that is complementary to the substrate
• What does it mean for an enzyme to be soluble?

  It can dissolve in water, allowing it to function in the cytoplasm
• What type of proteins are enzymes classified as?

  Globular proteins
• What bonds contribute to the tertiary structure of proteins?

  Ionic, hydrogen, and disulfide bonds
• What is the difference between intracellular and extracellular enzymes?

  Intracellular enzymes work inside cells, while extracellular enzymes work outside cells
• What is the significance of the enzyme-substrate complex?

  It lowers the activation energy required for the reaction
• How do cofactors and coenzymes assist enzymes?

  They help attract substrates and enhance enzyme activity
• What is the role of lactase?

  It catalyzes the breakdown of lactose into glucose and galactose
• What happens to lactase when it encounters lactose?

  It binds to lactose to form an enzyme-substrate complex
• What is the result of the hydrolysis of lactose by lactase?

  It produces glucose and galactose
• Why are enzymes too large to cross cell membranes?

  They are digested or broken down by other enzymes
• How do enzymes facilitate metabolic pathways?

  They catalyze specific reactions in a sequence of enzyme-controlled reactions