1. The most important metabolic fuel in the human body is: A. Sucrose
B. Starch
C. Protein
D. Cellulose
E. Glucose

2. When two monosaccharides undergo a condensation reaction:
A. a new monosaccharide is formed
B. a disaccharide is formed
C. a polysaccharide is formed
D. a starch is formed
E. hydrolysis occurs

3. Metabolism & Enzymes Constraints on Reactions
Making Reactions Possible with ATP
Making Reactions Probable with Enzymes
Why does Grandma take St. Joseph’s?

4. What is Metabolism?
All the chemical reactions of the body

5. What is Metabolism? All the chemical reactions of the body Catabolism
breaking large molecules into smaller molecules (hydrolysis)
releases energy (an exergonic process)

6. What is Metabolism? All the chemical reactions of the body Catabolism
breaking large molecules into smaller molecules (hydrolysis)
releases energy (an exergonic process)
Anabolism
builds a large molecule from smaller ones (dehydration synthesis/condensation)
consumes energy (an endergonic process)

7. Metabolism & Enzymes Constraints on Reactions
Making Reactions Possible with ATP
Making Reactions Probable with Enzymes
Why does Grandma take St. Joseph’s?

8. Constraints on Reactions
First Law of Thermodynamics
Energy can be converted from one form to another, but it cannot be created or destroyed
Chemical energy is stored in macromolecules we eat
When bonds are broken, energy is released
We use this energy to power our bodies

9. Constraints on Reactions
First Law of Thermodynamics
Energy can be converted from one form to another, but it cannot be created or destroyed
Chemical energy is stored in macromolecules we eat
When bonds are broken, energy is released
We use this energy to power our bodies
Second Law of Thermodynamics
In every energy transfer, some energy is lost as heat
Unless our bodies obtain energy from our surroundings, we lose energy over time (entropy)

10. To counter the loss of energy (as heat), we add energy to our bodies in the form of food

11. Using ATP to Build Macromolecules

12. Using ATP to Build Macromolecules
endergonic
exergonic

13. ATP is Recycled
(Breakdown of food)

14. Metabolism & Enzymes Constraints on Reactions
Making Reactions Possible with ATP
Making Reactions Probable with Enzymes
Why does Grandma take St. Joseph’s?

15. Enzymes are Everywhere

16. Enzymes are Biological Catalysts
Enzymes are proteins that function as biological catalysts
Increase the speed of chemical reactions
Increase likelihood of chemical reactions

17. Enzymes are Biological Catalysts
Enzymes are proteins that function as biological catalysts
Increase the speed of chemical reactions
Increase likelihood of chemical reactions
Can increase rate of chemical reactions by over 1,000,000X

18. Enzymes Bind to Substrates
Bind with one or more reactants, termed substrates

19. Enzymes Bind to Substrates
Bind with one or more reactants, termed substrates
Enzymes are named after the substrate with which they bind
-ase forms the suffix (e.g., the enzyme amylase digests the starch amylose)

20. How do Enzymes Work? Enzymes can affect reactions by:
1) Placing reactants in proper orientation
2) Create environment that promotes the reaction
3) Chemically weakening the bonds within the reactants
4) Donating electrons or protons to the reactants

21. How do Enzymes Work? Enzymes can affect reactions by:
1) Placing reactants in proper orientation
2) Create environment that promotes the reaction
3) Chemically weakening the bonds within the reactants
4) Donating electrons or protons to the reactants
Enzymes catalyze specific reactions

22. How do Enzymes Work? Enzymes can affect reactions by:
1) Placing reactants in proper orientation
2) Create environment that promotes the reaction
3) Chemically weakening the bonds within the reactants
4) Donating electrons or protons to the reactants
Enzymes catalyze specific reactions
Enzymes are reusable (i.e. recycled)

23. Enzymatic Reactions

24. Cofactors
Cofactors bind to enzyme and change its shape, creating an active site (e.g., iron, copper, zinc, magnesium or calcium ions)

25. Cofactors
Cofactors bind to enzyme and change its shape, creating an active site (e.g., iron, copper, zinc, magnesium or calcium ions)
Vitamins are used to make organic cofactors called coenzymes.
Many enzymes cannot function without cofactors.

26. Rate of Enzymatic Reactions
The basis for chemical reactions is molecular and collision
Molecular Motion Animation

27. Rate of Enzymatic Reactions
Rates of reactions are affected by various factors:
Substrate and enzyme concentration
Temperature pH
Why do these influence reaction rates?

28. Enzyme/Substrate Concentration
Slow at low concentration
Enzyme

29. Enzyme/Substrate Concentration
Slow at low concentration
Increase until point of saturation
Why does saturation occur?
Enzyme

30. Temperature
Slow at low temperatures
Reaction Rate
Temperature (°C)

31. Temperature Slow at low temperatures Slow at high temperatures
Explain rate at each arrow
Reaction Rate
Temperature (°C)

32. pH Enzymes function best within a specific pH range
Why does pH alter enzyme function?

33. Competitive Inhibition
Slow down enzyme function
Effect is reversible
Substrate
Active Site
Inhibitor
Enzyme
Enzyme

34. Non-Competitive Inhibition
Binds to enzyme away from active site
Substrate
Enzyme
Inhibitor

35. Non-Competitive Inhibition
Binds to enzyme away from active site
Substrate no longer binds to active site
Irreversible damage to enzyme function
- Mercury, Cyanide
Substrate
Enzyme
Inhibitor

36. Metabolism & Enzymes Constraints on Reactions
Making Reactions Possible with ATP
Making Reactions Probable with Enzymes
Why does Grandma take St. Joseph’s?

37. Aspirin is a Non-Competitive Inhibitor
Inhibits COX enzyme, which functions in blood platelet aggregation
What do blood platelets do?
Hence, Aspirin reduces risk of a heart attack

38. Patient Profile: Laurie
Ate a Cheese Omelet, Blueberry yogurt, and 2 glasses of chocolate milk at IHOP
Symptoms: Diarrhea, Nausea, Stomach Ache
What do you think Laurie suffers from?

39. Summary
Building macromolecules, is an anabolic process that requires energy released from the catabolism of adenosine triphosphate (ATP)
Enzymes bring together reactants and create an environment that favors a reaction
Like any protein, the structure of an enzyme is critical to its function. Environmental conditions, cofactors, and inhibitors alter the structures of enzymes and hence alter their functions