1. Section 2.5: Enzymes
Biology

2. Activation Energy
Energy that is needed for a chemical reaction to begin

3. Activation Energy
Energy that is needed for a chemical reaction to begin
Once the chemical reaction begins it can continue on its own at a certain rate

4. Activation Energy
Energy that is needed for a chemical reaction to begin
Once the chemical reaction begins it can continue on its own at a certain rate
The activation energy generally comes from an increase in temperature

5. Activation Energy
Energy that is needed for a chemical reaction to begin
Once the chemical reaction begins it can continue on its own at a certain rate
The activation energy generally comes from an increase in temperature
But, the reaction may be very slow

6. Activation Energy
Energy that is needed for a chemical reaction to begin
Once the chemical reaction begins it can continue on its own at a certain rate
The activation energy generally comes from an increase in temperature
But, the reaction may be very slow
Concentration of reactants is low

7. Activation Energy
Energy that is needed for a chemical reaction to begin
Once the chemical reaction begins it can continue on its own at a certain rate
The activation energy generally comes from an increase in temperature
But, the reaction may be very slow
Concentration of reactants is low
Difficult for the reactant to interact

8. Catalyst
Substance that decreases the activation energy needed to start a chemical reaction

9. Catalyst
Substance that decreases the activation energy needed to start a chemical reaction
Also increases the rate of the chemical reaction

10. Catalyst
Substance that decreases the activation energy needed to start a chemical reaction
Also increases the rate of the chemical reaction
Catalysts take part in reactions, but are not considered part of the reactants or products

11. Catalyst
Substance that decreases the activation energy needed to start a chemical reaction
Also increases the rate of the chemical reaction
Catalysts take part in reactions, but are not considered part of the reactants or products
This is because the catalyst is neither changed by the chemical reaction or used up during a chemical reaction

12. Chemical Reactions In An Organism
Must take place at an organism’s body temperature

13. Chemical Reactions In An Organism
Must take place at an organism’s body temperature
The activation energy cannot come from an increase in temperature

14. Chemical Reactions In An Organism
Must take place at an organism’s body temperature
The activation energy cannot come from an increase in temperature
Reactants are found in low concentrations

15. Chemical Reactions In An Organism
Must take place at an organism’s body temperature
The activation energy cannot come from an increase in temperature
Reactants are found in low concentrations
Your body is large for a small molecule, finding another reactant can be difficult

16. Enzymes
Catalysts for chemical reactions in living things

17. Enzymes Catalysts for chemical reactions in living things
Lower the activation energy

18. Enzymes Catalysts for chemical reactions in living things
Lower the activation energy
Increase the rate of chemical reactions

19. Enzymes Catalysts for chemical reactions in living things
Lower the activation energy
Increase the rate of chemical reactions
Reactions are reversible

20. Enzymes Catalysts for chemical reactions in living things
Lower the activation energy
Increase the rate of chemical reactions
Reactions are reversible
Therefore do not change the direction of the reaction

21. Enzymes Catalysts for chemical reactions in living things
Lower the activation energy
Increase the rate of chemical reactions
Reactions are reversible
Therefore do not change the direction of the reaction
Do not affect chemical equilibrium

22. Enzymes Are Proteins
Chains of amino acids

23. Enzymes Are Proteins Chains of amino acids
Enzymes are VERY dependent upon their structure to function properly

24. Enzymes Are Proteins Chains of amino acids
Enzymes are VERY dependent upon their structure to function properly
Temperature and pH can affect the shape and function/activity

25. Enzymes Are Proteins Chains of amino acids
Enzymes are VERY dependent upon their structure to function properly
Temperature and pH can affect the shape and function/activity
Generally work best at organisms body temp.

26. Enzymes Are Proteins Chains of amino acids
Enzymes are VERY dependent upon their structure to function properly
Temperature and pH can affect the shape and function/activity
Generally work best at organisms body temp.
At higher temps the enzyme breaks apart through loss of hydrogen bonds, and therefore cannot function

27. Enzyme Structure Is Function
Enzymes are specific

28. Enzyme Structure Is Function
Enzymes are specific
Shape allows for only specific reactants to bind to the enzyme

29. Enzyme Structure Is Function
Enzymes are specific
Shape allows for only specific reactants to bind to the enzyme
Substrates: specific reactants for an enzyme

30. Enzyme Structure Is Function
Enzymes are specific
Shape allows for only specific reactants to bind to the enzyme
Substrates: specific reactants for an enzyme
Substrates temporarily bind to enzymes

31. Enzyme Structure Is Function
Enzymes are specific
Shape allows for only specific reactants to bind to the enzyme
Substrates: specific reactants for an enzyme
Substrates temporarily bind to enzymes
Active Site: Binding place of substrate to enzyme

32. Enzyme Structure Is Function
Enzymes are specific
Shape allows for only specific reactants to bind to the enzyme
Substrates: specific reactants for an enzyme
Substrates temporarily bind to enzymes
Active Site: Binding place of substrate to enzyme

33. Lock And Key Model
Enzymes bring substrates close to active site

34. Lock And Key Model Enzymes bring substrates close to active site
Decrease activation energy

35. Lock And Key Model Enzymes bring substrates close to active site
Decrease activation energy
Becomes easier to break bonds between substrates

36. Lock And Key Model Enzymes bring substrates close to active site
Decrease activation energy
Becomes easier to break bonds between substrates
Allows the joining of the substrates

37. Lock And Key Model Enzymes bring substrates close to active site
Decrease activation energy
Becomes easier to break bonds between substrates
Allows the joining of the substrates
Then releases the product

38. Induced Fit Model
The binding of the substrate changes the shape of both the substrate and the enzyme

39. Induced Fit Model
The binding of the substrate changes the shape of both the substrate and the enzyme
This change in shape allows catalysis to occur

40. Induced Fit Model
The binding of the substrate changes the shape of both the substrate and the enzyme
This change in shape allows catalysis to occur
The induced fit model therefore is an expansion of the lock and key model

41. Types of Enzymes
Named for their reactions…

42. Types of Enzymes Named for their reactions…
Transferase: Move functional group from one molecule to another

43. Types of Enzymes Named for their reactions…
Transferase: Move functional group from one molecule to another
Ligase: Combining two molecules

44. Types of Enzymes Named for their reactions…
Transferase: Move functional group from one molecule to another
Ligase: Combining two molecules
Oxidoreductase: Two reactions, transferring electrons from one molecules to another

45. Types of Enzymes Named for their reactions…
Transferase: Move functional group from one molecule to another
Ligase: Combining two molecules
Oxidoreductase: Two reactions, transferring electrons from one molecules to another
Forward and reverse directions

46. Types of Enzymes Named for their reactions…
Transferase: Move functional group from one molecule to another
Ligase: Combining two molecules
Oxidoreductase: Two reactions, transferring electrons from one molecules to another
Forward and reverse directions
Isomerase: conversion of one molecule into another, without the loss of any molecules(generally a 3-D rearrangement)

47. Types of Enzymes Named for their reactions…
Transferase: Move functional group from one molecule to another
Ligase: Combining two molecules
Oxidoreductase: Two reactions, transferring electrons from one molecules to another
Forward and reverse directions
Isomerase: conversion of one molecule into another, without the loss of any molecules(generally a 3-D rearrangement)
Hydrolase: Add water to a molecule that breaks it apart into two separate molecules

48. Types of Enzymes Named for their reactions…
Transferase: Move functional group from one molecule to another
Ligase: Combining two molecules
Oxidoreductase: Two reactions, transferring electrons from one molecules to another
Forward and reverse directions
Isomerase: conversion of one molecule into another, without the loss of any molecules(generally a 3-D rearrangement)
Hydrolase: Add water to a molecule that breaks it apart into two separate molecules
Lyase: Break a molecule into two parts without the use of water