Enzymes

1. Enzymes Chapter 8

2. Learning Targets • I can describe the structure and explain the significance and functions of enzymes in biological systems • I can describe why an investment of activation energy is necessary to initiate a spontaneous reaction. • I can explain how enzymes speed up chemical reactions. • I can explain the interactions between substrates and active sites of enzymes. • I can explain how the following affect enzymatic function: • Enzyme and substrate concentrations • pH, temperature and salinity • coenzymes • inhibition; competitive, non-competitive and allosteric cooperativity • I can describe the role that enzymes play in feedback inhibition. • I can design a lab that quantifiably measures the effect of an environmental factor on enzymatic activity.

3. Structure • Protein • Each enzyme is substrate-specific: the active site is specifically shaped so only certain molecules fit on it

4. Learning Targets • I can describe the structure and explain the significance and functions of enzymes in biological systems • I can describe why an investment of activation energy is necessary to initiate a spontaneous reaction. • I can explain how enzymes speed up chemical reactions. • I can explain the interactions between substrates and active sites of enzymes. • I can explain how the following affect enzymatic function: • Enzyme and substrate concentrations • pH, temperature and salinity • coenzymes • inhibition; competitive, non-competitive and allosteric cooperativity • I can describe the role that enzymes play in feedback inhibition. • I can design a lab that quantifiably measures the effect of an environmental factor on enzymatic activity.

5. Activation Energy • How reactions work:

6. Learning Targets • I can describe the structure and explain the significance and functions of enzymes in biological systems • I can describe why an investment of activation energy is necessary to initiate a spontaneous reaction. • I can explain how enzymes speed up chemical reactions. • I can explain the interactions between substrates and active sites of enzymes. • I can explain how the following affect enzymatic function: • Enzyme and substrate concentrations • pH, temperature and salinity • coenzymes • inhibition; competitive, non-competitive and allosteric cooperativity • I can describe the role that enzymes play in feedback inhibition. • I can design a lab that quantifiably measures the effect of an environmental factor on enzymatic activity.

7. Enzymes are Catalysts

8. Induced Fit • Shape of active site can change slightly as substrate binds • The active site is then molded into a precise conformation--sort of like a hand in a glove • So, some enzymes canact on similarmolecules, not justspecificones

9. Learning Targets • I can describe the structure and explain the significance and functions of enzymes in biological systems • I can describe why an investment of activation energy is necessary to initiate a spontaneous reaction. • I can explain how enzymes speed up chemical reactions. • I can explain the interactions between substrates and active sites of enzymes. • I can explain how the following affect enzymatic function: • Enzyme and substrate concentrations • pH, temperature and salinity • coenzymes • inhibition; competitive, non-competitive and allosteric cooperativity • I can describe the role that enzymes play in feedback inhibition. • I can design a lab that quantifiably measures the effect of an environmental factor on enzymatic activity.

10. Enzyme-Substrate Interaction • How do the following relate to enzymes? • active site • substrate • induced fit • energy of activation

11. Learning Targets • I can describe the structure and explain the significance and functions of enzymes in biological systems • I can describe why an investment of activation energy is necessary to initiate a spontaneous reaction. • I can explain how enzymes speed up chemical reactions. • I can explain the interactions between substrates and active sites of enzymes. • I can explain how the following affect enzymatic function: • Enzyme and substrate concentrations • pH, temperature and salinity • coenzymes • inhibition; competitive, non-competitive and allosteric cooperativity • I can describe the role that enzymes play in feedback inhibition. • I can design a lab that quantifiably measures the effect of an environmental factor on enzymatic activity.

12. Enzyme-Substrate Concentration • Enzymes act on one molecule at a time • Reach a saturation point when all enzymes are engaged in reaction

13. pH, Temperature, Salinity • All enzymes have a specific range for optimal performance • Outside of that range  denature  don’t function

14. Denaturation

15. Inhibiting Factors Prevent/Interfere with Enzyme Function

16. Competitive Inhibition • Competitive inhibitor has same shape as substrate • (competes for active site) • Prevents substrate from binding to active site by binding to active site itself

17. Allosteric Inhibition • Inhibitor binds to allosteric site of enzyme • Active site changes shape, no substrate binds

18. Enhancing Factors Help/Increase Enzyme Function

19. Cofactors & Coenzymes • Cofactor assist with catalytic activities of enzyme • Coenzyme is an organic cofactor • Ex: vitamins

20. Allosteric Activation • Change in the enzyme’s shape due to binding of activator at allosteric site • Enzyme is stabilized by activator

21. Allosteric Cooperativity • One substrate molecule primes an enzyme to receive more substrates readily • Ex: hemoglobin

22. Learning Targets • I can describe the structure and explain the significance and functions of enzymes in biological systems • I can describe why an investment of activation energy is necessary to initiate a spontaneous reaction. • I can explain how enzymes speed up chemical reactions. • I can explain the interactions between substrates and active sites of enzymes. • I can explain how the following affect enzymatic function: • Enzyme and substrate concentrations • pH, temperature and salinity • coenzymes • inhibition; competitive, non-competitive and allosteric cooperativity • I can describe the role that enzymes play in feedback inhibition. • I can design a lab that quantifiably measures the effect of an environmental factor on enzymatic activity.

23. Feedback Inhibition • The switching off of a biochemical pathway by the product of the pathway • Negative feedback • Conserve energy!

24. Bozeman Enzymes Video

25. Learning Targets • I can describe the structure and explain the significance and functions of enzymes in biological systems • I can describe why an investment of activation energy is necessary to initiate a spontaneous reaction. • I can explain how enzymes speed up chemical reactions. • I can explain the interactions between substrates and active sites of enzymes. • I can explain how the following affect enzymatic function: • Enzyme and substrate concentrations • pH, temperature and salinity • coenzymes • inhibition; competitive, non-competitive and allosteric cooperativity • I can describe the role that enzymes play in feedback inhibition. • I can design a lab that quantifiably measures the effect of an environmental factor on enzymatic activity.

26. AP Lab 13 • Bozeman video