1. Bellwork: Tue. Sept. 20, 2016 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) 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, a test reagent that reacts positively with simple reducing sugars like maltose, will not react with starch. A positive test forms a brownish-red cuprous oxide precipitate. A weaker positive test will be yellow to orange –a negative result is blue.
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

2. 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!

3. Copyright Pearson Prentice Hall

4. 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.

5. 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.

6. 1. "Spit" between 1 to 2 mL of saliva into each test tube (A,B,C)
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.
vinegar
3. Place Test tube B in boiling water 5 min.
4. Cool test tube B
distilled water
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 2-3 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.

7. Copyright Pearson Prentice Hall

9. Copyright Pearson Prentice Hall
Orange = Positive Result:
This indicates that you have the sugar maltose in the solution, and that the protein enzyme in your saliva – amylase was denatured… you have to tell me why this happened in each test tube
Blue = Negative Result
This indicates that you DON’T have the sugar maltose in the solution, and that the protein enzyme in your saliva – amylase was NOT denatured… you have to tell me why this happened in each test tube
Copyright Pearson Prentice Hall

10. Copyright Pearson Prentice Hall
Bellwork: Wed. Sept. 21, 2016
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. Was 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?____________________________ 7. Why do you think this groups’ “B” turned orange?__________________________
Copyright Pearson Prentice Hall

11. 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

12. 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 12

13. 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?
______________________ ______________________ ______________________

14. When proteins lose structure by application of stress or compound
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
Activation 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”

17. 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? ____________________________

18. 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

19. Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall

20. Cell notes 3

21. sugar CHO energy glucose Veg. Oils, fat Unsaturated fatty acid energy
monosaccharide
Veg. Oils,
fat
Unsaturated
fatty acid
CHO (P)
Fatty acid
& glycerol
energy
phospholipid
Build bones
& muscles
Meat
amino acid
chains
CHON
amino acids

22. 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