1. Metabolism: Energy and Enzymes
Chapter 6

2. LAB Tues 9/13 *next week! Be there!
Fri 9/16: Unit test: Ch 2,3, & 6 QOD notebook due
Lab: biological science room 136http://

3. Biological Science building room 136 -13 on map extra 5 min to get there

4. QOD Staple/tape is the macromolecule graphic organizer as last QOD
What are the 4 shapes of proteins? Draw a small sketch to go with your explanation or each shape

5. Energy = the ability to do work
Kinetic Energy (energy of motion)
Potential Energy (stored energy)
First Law of Thermodynamics - the law of conservation of energy (not created or destroyed)
Second Law of Thermodynamics - energy cannot be changed without a loss of usable energy (heat)

6. Chemical Reaction Reactants Products
Reactants: starting substances, on the left side of the arrow.
Products: substances formed during the reaction, on the right side of the arrow.
Baking soda + vinegar
water + CO2
Reactants
Products

7. What are the reactants and products?
6CO2 + 6H2O
C6H12O6
Reactants
Products
H2O2
H2O + O2
Reactants
Products

8. Reactants --> Products
Metabolic Reactions
Reactants --> Products 
Exothermic - releases energy 
Endothermic = absorbs energy

9. This reaction is exothermic and released heat energy.
Chapter 6
Chemistry in Biology
This reaction is exothermic and released heat energy.
Aka: exergonic
The energy of the product is lower than the energy of the reactants.

10. This reaction is endothermic and absorbed heat energy.
Chapter 6
Chemistry in Biology
6.2 Chemical Reactions
This reaction is endothermic and absorbed heat energy.
Aka: endergonic
The energy of the products is higher than the energy of the reactants.

11. Gibbs free energy change:
Energy from exothermic reactions used to drive endothermic rxns

12. Metabolic Pathways & Enzymes (6-3)
Enzyme - protein molecule that functions as an organic catalyst to speed reactions
Substrate - reactants in the enzymatic reaction, this is what an enzyme attaches to
Activation Energy- the energy required to cause the reaction

13. activation energy: the minimum amount of energy needed for a reaction.
Chemistry in Biology
Energy of Reactions
activation energy: the minimum amount of energy needed for a reaction.
Enzymes lower the activation energy

14. Enzymes do not affect the Gibbs free energy change, just the activation energy

15. Properties of Enzymes:
Enzymes are made of proteins.
They speed up chemical reactions inside the cytoplasm.
They are needed only in small amounts
They remain unchanged after each reaction and can therefore be reused
Each enzyme is specific for a substrate

16. Substrates: reactants that bind to the enzyme
Chapter 6
Chemistry in Biology
Substrates: reactants that bind to the enzyme
active site: specific location where a substrate binds on an enzyme

17. Lock and Key Model
Each enzyme acts on a specific substrate

18. Induced Fit Model - substrates and enzymes fit together
Induced Fit Model - substrates and enzymes fit together like a lock and key. 
Degradation vs Synthesis
                 breaking down vs building

19. Factors Affecting Enzymatic Activity
1. Substrate/ enzyme concentration 2. Temperature & pH * 3. Presence of inhibitors
Enzymes can be denatured - they change shape so much that they are no longer effective. High temp or pH can cause denaturation by breaking the H-bonds of the protein 4D structure. 

21. Siamese cats have an enzyme that works at lower temperatures only, causing the nose and ears to become a darker color than the rest of the body.

22. Competitive Inhibition vs. Noncompetitive Inhibition (allosteric site)
Enzymatic Inhibition - when a substance binds to an enzyme and decreases its activity. (Usually reversible)
Competitive Inhibition  vs.
Noncompetitive Inhibition (allosteric site)
**Both are forms of feedback inhibition
Normal
Inhibited:
competitive
Non- competitive

24. Some inhibitors are NOT reversible - poisons like cyanide, lead poisoning all affect enzymes
QUESTION: What type of inhibition is pictured below?

25. Both cofactors and coenzymes help to complete the structure of a conjugated enzyme
CO-ENZYME is a small organic non-protein MOLECULE that carries chemical groups between enzymes ex: iron, magnesium or zinc.
CO-FACTOR is a non-protein CHEMICAL COMPOUND that is bound tightly to an enzyme and is required for catalysis.
ex: NAD+, NADP+ and FAD+

26. Enzyme Animation (Tutorial) 
Enzyme Quiz

27. Enzyme Lab 2H2O2 ----> 2H2O + O2
Hydrogen Peroxide is broken down by the enzyme catalase within cells.   
Potatoes hold the enzyme catalase, which will speed up the breakdown of hydrogen peroxide

28. Proteins have four shapes
1. Primary Structure - sequence of amino acids that form the polypeptide chain 2. Secondary Structure - Parts of the polypeptide fold into local patterns (alpha helix or pleated sheet) 3. Tertiary Structure - the overall 3D shape (globular or fibrous) 4. Quaternary Structure - consists of two or more polypeptide chains or subunits

29. Factors Affecting Enzymatic Activity
1. Substrate/ enzyme concentration 2. Temperature & pH * 3. presence of inhibitors
Enzymes can be denatured - they change shape so much that they are no longer effective. High temp or pH can cause denaturation. 

30. The activity of catalase can be seen by the bubbling of oxygen during the reaction
Generally speaking, catalase reactions occur faster at warmer temperatures.
If temperature is too hot (boiling) then the enzyme becomes denatured

31. Virtual Labs with Enzymes
McGraw Hill Lab
Bio 114  Enzymes
Lab Bench Enzyme Catalysis

32. ATP
Ribose (sugar)
release energy
Add energy
ADP
Diphosphate
Energy stored in ATP is released by breaking the bond between the 2nd and 3rd phosphates.

33. ATP
Energy stored in ATP is released by breaking the bond between the 2nd and 3rd phosphates.
2 Phosphate groups P
ADP
Copyright Pearson Prentice Hall

34. ATP - the energy currency of cells (adenosine triphosphate)
Functions: 1. CHEMICAL WORK - Supplies energy needed to make macromolecules that make up the cell (and organism) 2. TRANSPORT WORK - Supplies energy needed to pump substances across the cell membrane 3. MECHANICAL WORK - supplies energy needed to make muscles contract and other cellular parts to move (flagella)

35. How do cells make ATP? Cellular respiration Photosynthesis
Electron transport chain
Chemiosmosis= production of ATP due to hydrogen ion gradient across a membrane

38. ATP

39. redox reaction: oxidation-reduction reaction oxidized loses electrons, releasing energy a molecule that is reduced gains electrons, storing energy ADP + P  ATP NAD+ + 2e- + H+  NADP

40. Review videos

41. QOD: Enzyme review

42. FRQ example: An experiment was conducted to measure the reaction rate of the human salivary enzyme α-amylase. Ten mL of a concentrated starch solution and 1.0 mL of α-amylase solution were placed in a test tube. The test tube was inverted several times to mix the solution and then incubated at 25°C. The amount of product (maltose) present was measured every 10 minutes for an hour. The results are given in the table below.
(a) Graph the data on the axes provided and calculate the rate of the reaction for the time period 0 to 30 minutes.
(b) Explain why a change in the reaction rate was observed after 30 minutes.
(c) Draw and label another line on the graph to predict the results if the concentration of α-amylase was doubled. Explain your predicted results.
(d) Identify TWO environmental factors that can change the rate of an enzyme-mediated reaction. Discuss how each of those two factors would affect the reaction rate of an enzyme.

43. FRQ: interpreting graphs
FRQ: free response question - there are long and short versions - I have to be able to read your writing - they often ask for interpretation of data FRQ: Interpreting graphs:
FRQ: interpreting graphs
write at least a sentence per graph, interpreting the data in graph

45. You are here
136
Biological Science
Room #136