1. saturated fatty acid (left) unsaturated fatty acid (right)
The difference between a saturated and unsaturated fatty acid is that saturated fatty acids don’t have double bonds between carbon atoms and unsaturated fatty acids have double bonds between carbon atoms.
Saturated fats are considered unhealthy because they enter your bloodstream and stick togetther (bonding as plaque – which can clog your arteries and eventually lead to…
saturated fatty acid (left) unsaturated fatty acid (right)

2. 2–4 Chemical Reactions
And

3. Bellwork Mon. Sept. 24, 2018 1. 2. 3.

4. Chemical Reactions
A chemical reaction is a process that changes one set of chemicals into another set of chemicals.

5. Copyright Pearson Prentice Hall
What do energy changes do for living
things?
In order to stay alive, organisms need to carry out reactions that require energy. Every organism must have a source of energy to carry out chemical reactions.
Copyright Pearson Prentice Hall

6. Copyright Pearson Prentice Hall
Plants get their energy by trapping and storing the energy from sunlight in energy-rich compounds.
Copyright Pearson Prentice Hall

7. Copyright Pearson Prentice Hall
Animals get their energy when they consume plants or other animals.
Copyright Pearson Prentice Hall

8. Copyright Pearson Prentice Hall
Humans release the energy needed to grow tall, to breathe, to think, and even to
dream through the
chemical reactions that occur when humans metabolize, or break down, digested food.
Copyright Pearson Prentice Hall

9. like… 2H2 + O2  2H2O or… 6H2O + 6CO2 energy  C6H12O6 + 6O2
Reactant + Reactant  Product(s)
like…
2H O2  2H2O
or…
6H2O + 6CO2 energy  C6H12O6 + 6O2
Water carbon dioxide glucose oxygen

10. This enables the bloodstream to carry carbon dioxide to the lungs.
Your cells make CO2 which is carried to your lungs in the bloodstream. It’s eliminated as you exhale. But CO2 isn't very soluble in water. The bloodstream could not possibly dissolve enough carbon dioxide to carry it away from your tissues without a chemical reaction…
As it enters the blood, CO2 reacts with water to produce a highly soluble compound called carbonic acid, H2CO3.
H2O CO2  H2CO3
This enables the bloodstream to carry carbon dioxide to the lungs.

11. In the lungs, the reaction is reversed
H2CO3  H2O CO2

12. Reactants: elements or compounds that enter into a chemical reaction.
Products: elements or compounds produced by a chemical reaction.

13. Amylase is an enzyme in human saliva that catalyses the breakdown of starch into sugar – maltose – two linked glucose molecules. The chemical process of digestion begins the moment we put food into our mouth. Food that contains a lot of starch but very little sugar (potatoes and rice) taste slightly sweet as they are chewed because amylase turns some of their starch into sugar in our mouth!

14. Our pancreas also makes amylase to hydrolyze dietary starch into disaccharides and trisaccharides which are converted by other enzymes to glucose to supply the body with energy. Plants and some bacteria also produce amylase.

15. Copyright Pearson Prentice Hall
Enzyme activity of the stomach
Copyright Pearson Prentice Hall

16. Energy Changes
Chemical reactions that release energy often occur spontaneously.
Chemical reactions that absorb energy will not occur without a source of energy.

17. When hydrogen gas reacts with oxygen to produce water vapor, it is an energy-releasing reaction in which energy is given off as heat.
2H2 + O2 2H2O

18. Activation Energy: What chemists call the energy that is needed to get a reaction started
Chemical reactions that release energy often occur spontaneously. Chemical reactions that absorb energy will occur only with a source of energy. The peak of each graph represents the energy needed for the reaction to go forward. The difference between this required energy and the energy of the reactants is the activation energy.

19. Enzymes
Some chemical reactions that make life possible are too slow or have activation energies.
These chemical reactions are made possible by catalysts.

20. Catalyst: substance
that speeds up the
rate of a chemical
reaction

21. How do enzymes do their jobs?
For a chemical reaction to take place, reactants must collide with enough energy so existing bonds will be broken and new bonds will be formed. If the reactants do not have enough energy, they will be unchanged after the collision.

22. The Enzyme-Substrate Complex
Enzymes provide a site where reactants can be brought together to react. Such a site reduces the energy needed for reaction.
Substrates: reactants of enzyme-catalyzed reactions.

23. What is the function of an enzyme?
Enzymes proteins that speed up chemical reactions that take place in cells.

24. An Enzyme-Catalyzed Reaction
Enzyme Action
An Enzyme-Catalyzed Reaction
The enzyme is hexokinase. The substrates are glucose and ATP. During the reaction, a phosphate group is transferred from ATP to the glucose molecule.
The enzyme hexokinase converts the substrates glucose and ATP into glucose-6-phosphate and ADP.

25. Copyright Pearson Prentice Hall
Substrate fitting into an active site on an enzyme. They are bound by intermolecular forces and form an enzyme-substrate complex.
They remain bound together until the reaction is completed. Then products of the reaction are released and the enzyme is free to start the process again.
Copyright Pearson Prentice Hall

26. Copyright Pearson Prentice Hall
Each protein has a specific, complex shape. The substrates bind to a site on the enzyme called the active site.
The active site the substrates have complementary shapes. The fit is so precise that the active site and substrates are often compared to a lock and key.
Copyright Pearson Prentice Hall

27. Regulation of Enzyme Activity
Enzymes can be affected by any variable that influences a chemical reaction.
pH values
Changes in temperature
Enzyme or substrate concentrations

28. Cheese probably discovered by ancient hunters who stored milk in the stomachs of slaughtered calves. When exposed to heat, the milk inside the container would turn into a solid – cheese –because of an enzyme called chymosin in their stomachs.

29. Laundry detergents
Contain enzymes to dissolve proteins and fat  two of the major causes of stains on clothing. Grass, blood and egg are all protein stains. Lipstick, frying oil, butter, sauces, and tough stains on cuffs and collars are fat stains. to remove these stains without enzymes is difficult requiring lots of washing at high temperatures.

30. Denaturation of Proteins:
When proteins lose structure by application of stress or compound - reactions with:
1. a strong acid or base
2. an inorganic salt or organic solvent (e.g., alcohol)
3. heat

31. The elements or compounds produced by a chemical reaction are known as
2–4
The elements or compounds produced by a chemical reaction are known as
reactants.
enzymes.
products.
waste.

32. Copyright Pearson Prentice Hall
2–4
Chemical reactions always involve
changes in energy.
enzymes.
catalysts.
changes in the atomic number of the reactants.
Copyright Pearson Prentice Hall

33. Copyright Pearson Prentice Hall
2–4
The factor that prevents many energy-releasing reactions from occurring at relatively low temperatures is called
catalytic energy.
chemical bond energy.
enzyme energy.
activation energy.
Copyright Pearson Prentice Hall

34. Copyright Pearson Prentice Hall
2–4
Which of the following statements is true?
All proteins are enzymes.
All catalysts are enzymes.
All enzymes are catalysts.
All catalysts are proteins.
Copyright Pearson Prentice Hall

35. Copyright Pearson Prentice Hall
What happens to an enzyme after the reaction it catalyzes has taken place?
The enzyme is destroyed, and the cell must make another.
The enzyme holds on to the product until another enzyme removes it.
The enzyme is unchanged and ready to accept substrate molecules.
The enzyme changes shape so it can accept a different kind of substrate.
Copyright Pearson Prentice Hall

36. Bellwork: Monday Sept. 15, 2014 read the following
Enzyme Amylase Reaction on Starch
Introduction: Today you’ll observe the action of the enzyme amylase on starch. Amylase changes starch into a simpler form: the sugar maltose, which is soluble in water. Amylase is in our saliva, and begins to act on starchy food while in our mouth. Exposure to heat , extreme pH (acid or base) & an inorganic salt or organic solvent (e.g., alcohol) will denature proteins (like an egg white cooking) Enzymes, including amylase, are proteins. If denatured, an enzyme can no longer act as a catalyst for the reaction.
Benedict's solution is a test reagent that reacts positively with simple reducing sugars like maltose, but will not react with starch. A positive test is observed as the formation of a brownish-red cuprous oxide precipitate. A weaker positive test will be yellow to orange.
1. What enzyme is in your saliva?_____________________
2. What three things will denature a protein ________________, ________________, ____________________
3. Benedict’s solution turns ___________________ in the presence of the “sugar” ____________________ in this lab

37. Copyright Pearson Prentice Hall

38. PRE-LAB
I’m adding 1g (approx ¼ tsp) of cornstarch to a beaker containing 100ml of cold distilled water. While stirring frequently, heat the mixture just until it begins to boil. Allow to cool.

39. PRE-LAB: large batch Add 10g of cornstarch to a beaker containing 1000ml of cold distilled water. While stirring frequently, heat the mixture just until it begins to boil. Allow to cool.

40. 1. "Spit" between 1 to 2 mL of saliva into each test tube (A,B,C)
vinegar
2. Into tube A, add 2 mL of vinegar. Into tubes B and C, add 2 mL of distilled water.
Thump the tubes to mix.
3. Place Test tube B in boiling water 5 min.
distilled water
4. Cool test tube B
5. Add 5 mL of the starch solution to each tube and thump to mix. Allow the tubes to sit for 10 minutes, occasionally thumping the tubes to mix.
6. Add 2 mL of Benedict's solution to each tube and thump to mix. Place the tubes in the hot water bath. The reaction takes several minutes to begin.

41. Copyright Pearson Prentice Hall

46. Bellwork: Wed. Sept. 18,2013
Quiz

47. Copyright Pearson Prentice Hall
Each protein has a specific, complex shape. The substrates bind to a site on the enzyme called the active site.
The active site and the substrates have complementary shapes. The fit is so precise that the active site and substrates are often compared to a lock and key.
Copyright Pearson Prentice Hall 47

48. Bellwork: Wed Sept. 17, 2014 “QUIZ”
What is the function of an enzyme? _________________
 2. Where does a substrate attach to an enzyme?_________________
3. If an enzyme is present in a reaction, less ______________________ is needed to get the reaction started.
4. What is a common suffix found at the end of most biological enzymes? ______________
5. Most enzymes are macromolecules called ________________.
6. Define denaturation of proteins:__________________
  7. Name 3 things that can denature or unfold an enzyme. _________
 8. In this lab, what weak acid denatured the protein? _______________
9. What was the purpose of placing one test tube in a hot water bath?
_________________
10. What happens to enzymes in your body whenever you run a fever?
Speed up rate of reaction and lower activation energy
Active site
energy
-ase
protein
When proteins lose structure by application of stress or compound
1. strong acid or base 2. inorganic salt or organic solvent 3. heat
vinegar
to denature the protein (enzyme – amylase)
They are denatured - a virus is DNA or RNA and a protein coat - so the virus is “killed”

49. Tube A: Starch + saliva treated with vinegar (acid) 1
Tube A: Starch + saliva treated with vinegar (acid) 1. Was the test positive or negative?__________________ 2. What does this indicate?__________________________________ Tube B: Starch + saliva & water, treated in boiling water bath. 3. as the test positive or negative? ________________ 4. What does this indicate?________________________________ Tube C: Starch + saliva 5. Was the test positive or negative? _______________________ 6. What does this indicate? ____________________________

50. Denaturation of Proteins:
When proteins lose structure by application of stress or compound - reactions with:
1. a strong acid or base
2. an inorganic salt or organic solvent (e.g., alcohol)
3. heat

51. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall

52. Cell notes 3

53. All enzymes are macromolecules called proteins
The function of an enzyme:
speed up chemical reactions in organisms
by lowering activation energy!
All enzymes are macromolecules called proteins

54. Bellwork: Thurs. Sept. 19,2013 Correct your Quiz sugar CHO energy
glucose
monosaccharide
Veg. Oils,
fat
Unsaturated
fatty acid
CHO (P)
Fatty acid
& glycerol
energy
phospholipid
Build bones
& muscles
Meat
amino acid
chains
CHON
amino acids

55. A few hint for the crosswords: Mass: quantity of matter Orbital: region around the nucleus where electrons are located Aqueous: Solution in which water is the solvent

56. Bellwork: Mon. Sept. 16, 2013
Draw a picture of a water molecule and color it appropriately,
Add the appropriate charges
These uneven charges make the water molecule a ___________ molecule

57. Bellwork: Thurs. Sept 21, 2017
Name the 4 macromolecules in living things: 1___________________________ 2__________________________ 3___________________________ 4___________________________

58. After reading the short article answer the following in your notes:
Bellwork: Lipids – old
After reading the short article answer the following in your notes:
1. The difference between a saturated and unsaturated fatty acids is _____________
2. Saturated fats are considered unhealthy because _________________________
3. Process where glucose and fructose combine to form sucrose with the loss of one water molecule? _____________ ______________