Enzyme Action

• What is the primary structure of a protein?

  Sequence of amino acids
• What type of reaction forms a peptide bond?

  A condensation reaction
• What is the role of enzymes in biological reactions?

  • Speed up reactions
  • Lower activation energy
  • Act as biological catalysts
• What is the optimum temperature for enzyme activity?

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

  They denature and lose function
• What is denaturation in enzymes?

  Change in active site shape
• How do enzymes lower activation energy?

  By providing an alternative reaction pathway
• What is the lock and key theory of enzyme action?

  Substrate fits perfectly into active site
• What is the induced fit model of enzyme action?

  Active site changes shape to fit substrate
• What are the types of reactions catalyzed by enzymes?

  • Catabolic reactions: break down molecules
  • Anabolic reactions: build up molecules
• What is a catalyst?

  A substance that speeds up reactions
• What is the role of cofactors and coenzymes?

  Help enzymes work by attracting substrates
• What test is used to identify proteins?

  Biuret test
• What happens to lactase when it acts on lactose?

  It breaks down lactose into glucose
• How does the structure of enzymes relate to their function?

  Specific 3D shape allows substrate binding
• What are the bonds present in the tertiary structure of proteins?

  • Ionic bonds
  • Hydrogen bonds
  • Disulfide bonds
• What is the difference between intracellular and extracellular enzymes?

  Intracellular work inside cells, extracellular outside
• What is the significance of the active site in enzymes?

  It is where substrate binds for reaction
• What does "complementary shape" mean in enzyme action?

  Active site and substrate fit together
• How does the induced fit model improve enzyme efficiency?

  It allows tighter binding of substrate
• What is the process of substrate breakdown by an enzyme?

  1. Substrate enters active site
  2. Induced fit changes active site shape
  3. Enzyme-substrate complex forms
  4. Activation energy is lowered
  5. Bonds in substrate are stressed and broken
  6. Products are released
• What happens to enzymes when they are digested?

  They are broken down by other enzymes
• Why do enzymes not cross cell membranes?

  They are too large to enter bloodstream
• What are the key differences between the lock and key model and the induced fit model?

  • Lock and Key: perfect fit, no shape change
  • Induced Fit: similar shape, active site changes
• What color change indicates a positive Biuret test for proteins?

  Blue to purple
• What is the role of amylase?

  Convert carbohydrates into sugars
• What is the role of protease?

  Convert proteins into amino acids
• What is the role of lipase?

  Convert lipids into fatty acids and glycerol
• What is metabolism?

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

  Enzymes catalyze specific reactions only
• What is a metabolic pathway?

  Sequence of enzyme-controlled reactions
• What is the product of an enzyme-catalyzed reaction?

  Molecule(s) produced by enzymes
• What is the significance of the R groups in amino acids?

  They determine the properties of amino acids
• What is the role of water in hydrolysis reactions?

  It breaks down larger molecules
• What is the effect of pH on enzyme activity?

  It can alter enzyme shape and function
• How do ionic, hydrogen, and disulfide bonds affect protein structure?

  They stabilize the 3D shape of proteins
• What is the significance of the enzyme-substrate complex?

  It lowers activation energy for reactions
• What happens to products after an enzyme-catalyzed reaction?

  They are released from the active site
• How does the enzyme's 3D shape relate to its specificity?

  Specific shape allows binding to specific substrates
• What is the role of vitamins in enzyme function?

  They often act as cofactors or coenzymes