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Enzyme Action PowerPoint Presentation
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Enzyme Action

Enzyme Action

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Enzyme Action

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  1. 18th October Enzyme Action Learning objective: to describe different models for enzyme action and to investigate factors which control the rate of an enzyme reaction More free powerpoints at www.worldofteaching.com

  2. Lock and Key

  3. Lock and Key However certain substances can bind to the enzyme at sites other than the Active site and modify its activity (inhibitors/co-factors) Idea that the enzyme is flexible

  4. Induced Fit

  5. Enzyme reactions enzyme + substrate enzyme-substrate complex

  6. Enzyme reactions enzyme + substrate enzyme-substrate complex E +S ES

  7. Enzyme reactions enzyme + substrate enzyme-substrate complex E +S ES enzyme + product enzyme-substrate complex ES E +P

  8. Enzyme activity How fast an enzyme is working Rate of Reaction

  9. Enzyme activity How fast an enzyme is working Rate of Reaction Rate of Reaction = Amount of substrate changed (or amount product formed) in a given period of time.

  10. Enzyme activity Rate of Reaction Variable you are looking at

  11. Enzyme activity Four Variables

  12. Enzyme activity Temperature pH Four Variables Enzyme Concentration Substrate Concentration

  13. Temperature Rate of Reaction

  14. Temperature Rate of Reaction 0 10 20 30 40 50 60

  15. Temperature 5- 40oC Increase in Activity 40oC - denatures Rate of Reaction 0 10 20 30 40 50 60 <5oC - inactive

  16. Effect of heat on enzyme activty If you heat the protein above its optimal temperature bonds break meaning the protein loses it secondary and tertiary structure

  17. Effect of heat on enzyme activty Denaturing the protein

  18. Effect of heat on enzyme activty Denaturing the protein ACTIVE SITE CHANGES SHAPE SO SUBSTRATE NO LONGER FITS Even if temperature lowered – enzyme can’t regain its correct shape

  19. pH Rate of Reaction

  20. pH Rate of Reaction 1 5 7 8 9 2 3 4 6

  21. pH Narrow pH optima Rate of Reaction 1 5 7 8 9 2 3 4 6

  22. pH Narrow pH optima WHY? Rate of Reaction 1 5 7 8 9 2 3 4 6

  23. pH Narrow pH optima Disrupt Ionic bonds - Structure Rate of Reaction Effect charged residues at active site 1 5 7 8 9 2 3 4 6

  24. Enzyme Concentration Rate of Reaction

  25. Enzyme Concentration Rate of Reaction Enzyme Concentration

  26. Substrate Concentration Rate of Reaction

  27. Substrate Concentration Rate of Reaction Substrate Concentration

  28. Substrate Concentration Active sites full- maximum turnover Rate of Reaction Substrate Concentration