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2-4 Enzymes

2-4 Enzymes. Question:. What are enzymes ?. Enzymes. Answer: 1. Proteins: most enzymes are proteins . 2. Catalyst: chemical agent that accelerates a reaction without being permanently changed in the process. Enzymes.

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2-4 Enzymes

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  1. 2-4 Enzymes

  2. Question: • What are enzymes?

  3. Enzymes Answer: 1. Proteins: most enzymes are proteins. 2. Catalyst:chemical agent that accelerates a reaction without being permanently changed in the process.

  4. Enzymes 3. Selective: enzymes are specific for which they will catalyze (speed up) 4. Recycled:enzymes are reusable. 5. “ase” endings: examples: sucrase maltase lactase

  5. Question: • How do enzymes work?

  6. Enzymes Answer: • Enzymes speed up the cell’s chemical reactions by lowering the free energy of activation.

  7. Without Enzyme With Enzyme Free Energy Free energy of activation Reactants Products Progress of the reaction Enzymes

  8. Enzyme Substrate Substrate • The substance (reactant) an enzyme acts on.

  9. Substrate Enzyme Active Site Active Site • A restricted regionof an enzyme molecule which binds to the substrate.

  10. Active Site substrate Enzyme induced fit Induced Fit • Achange in the configuration of an enzyme’sactive site(H and ionic bonds are involved). • Induced by the substrate.

  11. substrate (Peroxide) + enzyme (Catalase in potato) enzyme-substrate complex  products + enzyme and + catalase WaterOxygen Enzymatic Reaction

  12. https://www.youtube.com/watch?v=6V_B3vJHdgg

  13. What Affects Enzyme Activity? • Two factors: 1. Environmental Conditions 2. Concentration of enzyme and substrate

  14. 1. Environmental Conditions • Enzymatic reactions are very specific. The following environmental conditions affect enzymatic reactions: 1. Temperature (extremes most dangerous): - high temps may denature theenzyme. 2. pH (most like 6 - 8 pH - neutral)

  15. Concentrations A. the concentration of enzyme • Increasing enzyme concentration will increase the enzyme reaction rate. B. the concentration of substrate • A higher concentration of substrate does not increase the reaction rate.

  16. Mini Activity #1

  17. Mini Activity #1 • One person’s fingers are the enzyme TOOTHPICKASE(one person is the timer, and one is the recorder) • The toothpicks are the SUBSTRATE • Toothpickase is a DIGESTIVE ENZYME. It breaks down toothpicks into two units. • To break the toothpick, place a toothpick between the thumb and the first finger of each hand. Break the toothpick in two pieces. • ALWAYS place broken toothpicks back in the container, and no peeking when breaking toothpicks!

  18. Mini Activity #1 • 1. What was the enzyme? • 2. What was the substrate? • 3. What did you notice happening to the substrate as time passed? • 4. Did the enzyme ever change? Why?

  19. Mini Activity #2 What were to happen if we increased the concentration of rubber bands while the number of toothpicks stayed the same?

  20. Mini Activity #2

  21. Mini Activity #2 • 1. Why does toothpickase only bind to toothpicks and not rubber bands? • 2. What happens when the concentration of rubber bands is higher than the concentration of toothpicks? • 3. What would occur to the reaction rate if there were a higher concentration of toothpickase enzymes?

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