1. Origin of Life Atoms make up molecules C, H, O, N, P combine and may form CH 4, H 2 O, NH 3, H 2, PO 4 3- Molecules form monomers CH 4, H 2 0, NH 3 may combine and form amino acids Monomers combine to form polymers Amino acids form proteins 1

2. Definitions ___________: a single unit molecule that may chemically bind to other molecules Ex. ___________________: building blocks of protein ___________: a chain of repeated monomers Ex. _____________: a large molecule formed by linked monomers called amino acids 2

3. Enzymes: special type of protein __________: a type of ________ that speeds up chemical _________ in living organisms without being _________ or destroyed. Chemical reactions are synonymous with metabolic reactions in biology. Are picky and only work on one molecule Example: catalase only works with H 2 O 2 (hydrogen peroxide) 3

4. CHEMICAL REACTIONS Transfer of Energy Rearrangement of Atoms 4

5. Energy Definitions: Ability to do work Ability to move or change matter Energy comes in ______ forms. 5

6. Forms of energy Light - sun Heat - shivering Mechanical - rub hands together Electrical - shock metal door knob Chemical - combustion 6

7. Chemical Reactions Energy is transferred Atoms are rearranged 7

8. Energy is Transferred First Law of Thermodynamics: The total amount of energy in an isolated system is constant (not increasing or decreasing). Energy cannot be created nor destroyed. 8

9. Rearrangement of Atoms __________: starting materials Product: newly formed substances  : changes into A + B  C + D Ex. HCl + KOH  KCl + H 2 O 9

10. Energy in Chemical Reactions Chemical bonds are formed and broken Hydrogen Bonds, Ionic Bonds, Covalent Bonds Products can either _______ or _______ energy Endothermic Reaction Exothermic Reaction -gonic = suffix meaning energy 10

11. Chemical Bonds and Reactions Are strong bonds easier or harder to break compared to weak bonds? And do they require more or less energy? Therefore, weak bonds are _________ to break and require ________ energy to do so. Do spontaneous reactions break ‘more stable’ or ‘less stable’ bonds? Why? 11

12. RULE OF THUMB The more strong bonds a molecule has, the more stable it is; consequently, more energy is needed to break down the molecule. 12

13. What is happening in this reaction? 13

14. How would you graph the diagram to the right? 14 Energy (heat) Time High Low

15. Endergonic Reaction Energy is absorbed Unfavorable or _________________ Products are less stable than reactants Ex 1. Photosynthesis 6CO 2 + 6H 2 O  C 6 H 12 O 6 + 6O 2 Ex 2. burning paper 15

16. What is happening in this reaction? 16

17. How would you graph the diagram to the right? 17 Energy (heat) Time High Low

18. Exergonic Reaction Energy is released Favorable or spontaneous Products more stable Ex. Respiration C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 18

19. Enzymes and Metabolic Reactions Endergonic Reaction Energy is _________ Products have ______ energy than reactants Exergonic Reaction Energy is __________ Products have ______ energy than reactants 19

20. Starting Chemical Reactions How do endergonic and exergonic reactions begin? 20

21. Activation Energy Activation energy (E A ): the energy needed to ________ a reaction Do spontaneous reactions require E A ? Do non-spontaneous reactions require E A ? 21

22. Enzyme and E A (Activation Energy) 22

23. Role of Enzyme 23

24. Enzymes protein that speeds up metabolic reactions Catalysts: _______ the activation energy needed to start a chemical reaction How do enzymes speed up chemical reactions? 24

25. Importance of Enzymes Allow organisms to maintain homeostasis Without enzymes, reactions would occur too slowly for life to exist Enzymes lower the activation energy needed for chemical reactions to occur = quicker reactions 25

26. Enzyme Specificity Specificity- specific, particular, precise Enzymes only work with certain _____________ or reactants. ____________: substance or molecule which an enzyme acts on Starch glucose H 2 O 2 2H 2 O + O 2 26 Amylase Catalase

27. How are enzymes specific? 27

28. Enzyme Lock and Key Model 28

29. What effects the performance of enzymes? Two things. Discuss with your table partner for a few moments. 29

30. 30

31. 31

32. THE END 32