2. Regents Biology Enzymes: “Helper” Protein molecules

3. Regents Biology Flow of energy through life  Life is built on chemical reactions

4. Regents Biology Chemical reactions of life  Processes of life  building molecules  synthesis  breaking down molecules  digestion ++

5. Regents Biology Nothing works without enzymes!  How important are enzymes?  all chemical reactions in living organisms require enzymes to work  building molecules  synthesis enzymes  breaking down molecules  digestive enzymes  enzymes speed up reactions  “catalysts” ++ enzyme We can’t live without enzymes!

6. Regents Biology Examples  synthesis  digestion ++ enzyme

7. Regents Biology Examples  dehydration synthesis (synthesis)  hydrolysis (digestion) enzyme

8. Regents Biology Enzymes are proteins  Each enzyme is the specific helper to a specific reaction  each enzyme needs to be the right shape for the job  enzymes are named for the reaction they help  sucrase breaks down sucrose  proteases breakdown proteins  lipases breakdown lipids  DNA polymerase builds DNA Oh, I get it! They end in -ase

9. Regents Biology Enzyme vocabulary  Enzyme  helper protein molecule  Substrate  molecule that enzymes work on  Products  what the enzyme helps produce from the reaction  Active site  part of enzyme that substrate molecule fits into

10. Regents Biology Enzymes aren’t used up  Enzymes are not changed by the reaction  used only temporarily  re-used again for the same reaction with other molecules  very little enzyme needed to help in many reactions enzyme substrateproduct active site

11. Regents Biology It’s shape that matters!  Lock & Key model  shape of protein allows enzyme & substrate to fit  specific enzyme for each specific reaction

12. Regents Biology 1 2 3

13. 2007-2008 Factors that Affect Enzymes

14. Regents Biology Factors Affecting Enzyme Function  Enzyme concentration  Substrate concentration  Temperature  pH  Salinity catalase

15. Regents Biology Enzyme concentration enzyme concentration reaction rate What’s happening here?!

16. Regents Biology Factors affecting enzyme function  Enzyme concentration  as  enzyme =  reaction rate  more enzymes = more frequently collide with substrate  reaction rate levels off  substrate becomes limiting factor  not all enzyme molecules can find substrate enzyme concentration reaction rate

17. Regents Biology Substrate concentration substrate concentration reaction rate What’s happening here?!

18. Regents Biology Factors affecting enzyme function substrate concentration reaction rate  Substrate concentration  as  substrate =  reaction rate  more substrate = more frequently collide with enzyme  reaction rate levels off  all enzymes have active site engaged  enzyme is saturated  maximum rate of reaction

19. Regents Biology 37° Temperature temperature reaction rate What’s happening here?!

20. Regents Biology Factors affecting enzyme function  Temperature  Optimum T°  greatest number of molecular collisions  human enzymes = 35°- 40°C  body temp = 37°C  Heat: increase beyond optimum T°  increased energy level of molecules disrupts bonds in enzyme & between enzyme & substrate  H, ionic = weak bonds  denaturation = lose 3D shape (3° structure)  Cold: decrease T°  molecules move slower  decrease collisions between enzyme & substrate

21. Regents Biology Enzymes and temperature  Different enzymes function in different organisms in different environments 37°C temperature reaction rate 70°C human enzyme hot spring bacteria enzyme (158°F)

22. Regents Biology How do ectotherms do it?

23. Regents Biology 7 pH reaction rate 20134568910 pepsintrypsin What’s happening here?! 11121314 pepsin trypsin

24. Regents Biology Factors affecting enzyme function  pH  changes in pH  adds or remove H +  disrupts bonds, disrupts 3D shape  disrupts attractions between charged amino acids  affect 2° & 3° structure  denatures protein  optimal pH?  most human enzymes = pH 6-8  depends on localized conditions  pepsin (stomach) = pH 2-3  trypsin (small intestines) = pH 8 72013456891011

25. Regents Biology Salinity salt concentration reaction rate What’s happening here?!

26. Regents Biology Factors affecting enzyme function  Salt concentration  changes in salinity  adds or removes cations (+) & anions (–)  disrupts bonds, disrupts 3D shape  disrupts attractions between charged amino acids  affect 2° & 3° structure  denatures protein  enzymes intolerant of extreme salinity  Dead Sea is called dead for a reason!

27. Regents Biology 2009-2010 For enzymes… What matters? SHAPE!

28. Regents Biology  Title: LAB 2: Factors Affecting Enzyme Activity  Introduction: (What is the purpose of this lab?)  Lab Report  4 sections  Title: (ex: Enzyme Concentration)  Introduction: Purpose of this specific experiment/what is your hypothesis?  Results and Data: (Data table and graph)  Conclusion (Explain your results, was your hypothesis supported, sources of error/improvement)  Questions (1-4)