Download Protein Unit Study Guide/Review Sheets

Protein Unit Study Guide/Review Sheets
You should begin studying now for your test on Thursday!
If you have questions, make sure to ask them. Stop in before or after school.
Review questions:
1. What elements comprise proteins? C, H, O, N
2. Are proteins organic? YES – CONTAIN CARBON AND HYDROGEN, THE
REQUIREMENT FOR BEING AN ORGANIC MOLECULE
3. What is the name of the monomer of proteins? AMINO ACID
4. What type of bond links amino acids together? PEPTIDE BONDS
5. What group on an amino acid differentiates it from, for example, a carbohydrate? AMINO
GROUP (NH2)
6. Is the group from question #5 the same or different on each amino acid? THE SAME – ALL
AMINO ACIDS HAVE AN AMINO GROUP
7. How many standard amino acids are there? 20
8. How many (of the standard amino acids) can our bodies synthesize? 11
9. What are the amino acids that our body can synthesize named? NONESSENTIAL
10. How many (of the standard amino acids) can’t our bodies synthesize? 9
11. What are the amino acids that our body can’t synthesize named? ESSENTIAL
12. If our bodies can’t synthesize certain amino acids, where do we get them from? OUR DIET
(FOOD)
13. Why is it important that we have all of the twenty amino acids? IF YOU DID NOT HAVE
ALL THE BUILDING BLOCKS NEEDED TO MAKE PROTEINS YOU, YOU
WOULDN’T BE ABLE TO MAKE CERTAIN PROTEINS; FOR EXAMPLE, IF YOU
DIDN’T HAVE AMINO ACID #6, YOU COULDN’T MAKE ANY OF THE PROTEINS
THAT CONTAIN AMINO ACIDS #6
14. What group on an amino acid differentiates it from the next amino acid? (What is different
between each of the 20 standard amino acids?) R GROUP; THE R GROUP IS
DIFFERENT ON EACH AMINO ACID; THERE ARE 20 DIFFERENT R GROUPS
15. What neutral molecule is formed when amino acids bonds together? WATER
16. What is the name of a molecule that has two amino acids linked together? DIPEPTIDE
17. What are the names of a molecule that has 100 amino acids linked together (two answers)?
POLYPEPTIDE, PROTEIN
18. Explain how three different proteins can be composed of 50 amino acids. THERE ARE A
COUPLE WAYS:
SAME AMINO ACIDS, 3 DIFFERENT ORDERS
DIFFERENT AMINO ACIDS
19. What makes a protein complete? A PROTEIN IS COMPLETE IF IT CONTAINS ALL OF
THE ESSENTIAL AMINO ACIDS
20. What are food sources of complete proteins? ANIMAL PRODUCTS; MEAT, MILK
21. What makes a protein incomplete? A PROTEIN IS INCOMPLETE IF IT DOES NOT
CONTAIN ALL OF THE ESSENTIAL AMINO ACIDS
22. List food sources of incomplete proteins. VEGETABLES
23. How can a vegetarian get all the amino acids that they need? BY EATING SEVERAL TYPES
OF INCOMPLETE PROTEINS, THEY WILL BE ABLE TO GET ALL OF THE AMINO
ACIDS THEY NEED; EACH PROTEIN IS INCOMPLETE FOR SOME OF THE
ESSENTIAL AMINO ACIDS ONLY  IF 1 INCOMPLETE PROTEIN HAS 8 OF THE 9
ESSENTIAL AMINO ACIDS AND ANOTHER HAS THE 1 AMINO ACID THAT THE
1
FIRST PROTEIN DOESN’T, TOGETHER, A PERSON GETS ALL OF THE
ESSENTIAL AMINO ACIDS
24. Define enzyme. SPECIALIZED PROTEINS THAT CATALYZE BIOCHEMICAL
REACTIONS
25. Define activation energy. THE AMOUNT OF ENERGY NEEDED FOR A CHEMICAL
REACTION TO OCCUR.
26. Describe specifically how enzymes speed up chemical reactions that otherwise would not occur.
ENZYMES LOWER THE ACTIVATION ENERGY, SO IT IS REACHED QUICKER, AND THE
REACTION CONCEQUENTLY HAPPENS FASTER
27. Why is an enzyme’s shape so important? Explain the “lock and key” model. EACH ENZYME
ONLY CATALYZES ONE SPECIFIC REACTION; FOR EXAMPLE CATALASE ONLY
CATALYZES THE REACTION H202  H2O + O2; THE STRUCTURE OF THE
ENZYME, CATALASE, MUST FIT THE STRUCTURE OF THE SUBSTRATE, H2O2,
PERFECTLY OR THE REACTION CANNOT BE CATALYZED AND WILL NOT
HAPPEN; THIS “FITTING” IS REFERRED TO AS THE LOCK AND KEY (ENZYMESUBSTRATE COMPLEX)
28. Are enzymes reusable? YES
29. Why must enzymes be reusable? SINCE THEY ARE REQUIRED FOR ALMOST EVERY
BIOCHEMICAL REACTION IN LIVING ORGANISMS, IT WOULD SIMPLY
IMPOSSIBLE TO POWER THE PRODUCTION OF A NEW ENZYME EVERY TIME
IT IS NEEDED
30. Do enzymes get used up in chemical reactions? NO
31. Relate your answers for questions #27-29. ENZYMES ARE REUSABLE BECAUSE
LIVING ORGANISMS SIMPLY COULD NOT MAKE ENOUGH ENZYMES TO
CATALYZE REACTIONS IF THEY ONE USE ONLY; SINCE THEY ARE
REUSUABLE, IT IS INHERANT THAT THEY ARE NOT USED UP IN CHEMICAL
REACTION; IF THEY WERE USED UP, THEY COULDN’T BE REUSED!!
32. Are enzymes a reactant, product, or neither of a chemical reaction? NEITHER. THEY ARE
NOT PART OF THE CHEMICAL REACTION, THEY JUST MAKE THE CHEMICAL
REACTION HAPPEN FASTER
33. Label this chemical equation with the words reactant(s), product(s), and substrate(s)
A+B+C+DE+F
A,B,C,D ARE REACTANTS; THEY ARE ALSO THE
SUBSTRATES, WHAT ENZYMES ACT UPON; E AND F ARE PRODUCTS; THEY
ARE PRODUCED DURING THIS CHEMICAL REACTION; THE POINT OF THE
ARROW IS ALWAYS POINTING TOWARDS THE PRODUCTS, ILLUSTRATING
THE REACTANTS ARE CHANGED INTO PRODUCTS
34. Can proteins provide energy? YES, 4 KCALS/GRAM
35. Explain why proteins are generally not used as a source of energy. PROTEINS HAVE SO
MANY VARIOUS VITAL ROLES THAT IT IS NOT FAVORABLE TO USE THEM FOR
ENERGY
36. How do proteins protect you from illness? SOME PROTEINS FUNCTION AS
ANTIBODIES, WHICH “MARK” FOREIGN INVADERS (BACTERIA, VIRUSES)
FOR DESTRUCTION
37. How are proteins involved in letting your body know what to do and when to do it? SOME
PROTEINS ARE HORMONES; HORMONES SIGNAL ANOTHER PART OF YOUR
BODY TO DO SOMETHING, MAKE SOMETHING, ETC.
38. How are proteins involved in, for example, getting oxygen to your cells? SOME PROTEINS
FUCTION AS TRANSPORTERS AROUND YOUR BODY (LIKE HEMOGLOBIN
DELIVERING OXYGEN TO YOUR CELLS); SOME PROTEINS FUNCTION AS
TRANSPORTERS FROM THE OUTSIDE OF A CELL OR MEMBRANE TO THE
INSIDE OF A CELL OR MEMBRANE (LIKE ATP SYNTHASE LETTING H+ IONS
THROUGH THE MEMBRANE DURING CHEMIOSMOSIS)
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39. What structural role do proteins fulfill? PROTEINS FORM HAIR, NAILS, MUSCLES,
TENDONS AND LIGAMENTS
40. Explain what this graph is demonstrating: THE RATE OF REACTION INCREASES AS
SUBSTRATE CONCENTRATION INCREASES
41. Explain what this graph is demonstrating: THE RATE OF REACTION INCREASES AS
ENZYME CONCENTRATION INCREASES (REFER TO GRAPH FROM #41)
42. What will happen to the rate of an enzyme reaction as the concentration of substrate is
increased from zero? E. IT WILL INCREASE, THEN LEVEL OFF (REFER TO GRAPH FROM
#40)
43. Explain what happens to this enzyme’s activity at 55 degrees AND WHY: THE ENZYME
STOPS WORKING BECAUSE IT IS TOO FAR AWAY FROM ITS OPTIMUM
TEMPERATURE OF 40; IT MAY BE DENATURED, WHICH MEANS ITS SHAPE
HAS BEEN CHANGED; SINCE ENZYME FUNCTION DEPENDS SO MUCH ON
SHAPE, IF ITS SHAPE IS CHANGED, IT CAN’T FUNCTION (SEE QUESTION #27)
44. What will happen to the rate of an enzyme reaction as it is heated from very cold (near
freezing) to very hot (near boiling)? B. IT WILL INCREASE, THEN DECREASE (REFER
TO GRAPH FROM #43)
45. At which pH do enzymes function best? E. THE OPTIMAL PH DEPENDS ON THE
PARTICULAR ENZYME.
46. Catalase catalyzes the conversion of H2O2 to 2H2O + O2. When you did this experiment, how
could you tell that a reaction was occurring? BUBBLES SIGNALED THAT PRODUCTS
WERE BEING FORMED (OXYGEN)
47. What is/are the substrate(s) in the reaction from #44? HYDROGEN PEROXIDE H2O2
48. What is/are the product(s) in the reaction from #44? OXYGEN AND WATER
49. What is the purpose of this enzyme in living tissue? TO BREAK DOWN POISONOUS H202
TO HARMLESS WATER AND OXYGEN
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