Category: Chemistry of Organisms

Chapter 2 Worksheet BI – Chemistry

 

Chemistry Worksheet

 

Section  2-1    Composition of Matter  

1. Define matter.

2. Define mass.

3. Explain the difference between mass & weight.

4. Why do biologists study chemistry?

5. Define element.

6. Name the 4 elements that make up 90% of the mass of living things. Give the symbol for each of these elements.

7. Explain why some elements such as sodium have odd symbols.

8. Sketch a block from the periodic table and label the atomic number, atomic mass, & symbol for the element.

9. Define atom and tell whether they can be seen.

10. What is the center of an atom called & what 2 subatomic particles are found there?

11. How does the charge of a proton differ from the charge of a neutron?

12. Where is most of the mass of an atom concentrated?

13. How is the atomic number of an element determined?

14. What is the charge on an electron?

15. Explain why the overall or net charge on an atom is zero.

16. Where are electrons found in an atom & describe their movement?

17. In which energy levels do the electrons have more energy?

18. How many electrons can these energy levels hold   — a. first?        b. second? 

19. Define compound and write a formula for water, carbon dioxide, & sodium chloride (table salt).

20. Do compounds have the same chemical properties as the elements that compose them?

21. When would an atom be chemically stable (not react)?

22. What occurs in a chemical reaction?

23. What is a covalent bond?

24. Define molecule.

25. Give an example of a gas that exists as a molecule.

26. Define ionic bond.

27. What is an ion?

28. Name a compound formed from — a. covalent bonding?            b. ionic bonding?

29. If electrons are shared, a(n) ______________ compound forms.

30. If electrons are transferred, a(n) _____________ compound forms.

31. Forming ionic or covalent bonds helps make atoms more ________________.

Section 2-2    Energy 

32. All living things require _____________ to do work.

33. Energy can’t be created or _____________ in a chemical reaction, but it can be _____________ from one form into another.

34. Name 4 forms of energy important to living things.

35. What is free energy?

36. Give an example of energy changing form in an organism.

37. Atoms & molecules are in constant _______________.

38. Name the 3 main states of matter.

39. Explain how the shape and volume of a solid, liquid, and gas differ.

40. Organisms undergo thousands of ____________ as part of their life processes.

41. Where are the reactants and products in a chemical equation?

42. What does a two-direction arrow mean in a chemical equation?

43. _______________ are broken down in chemical reactions in your body to release ___________ and produce _______________ and ______________.

44. What is the difference between an endergonic & exergonic reaction?

45. What is activation energy?

46. What effect does a catalyst have on activation energy?

47. What are biological catalysts called?

48. Redox is the abbreviation for what type of reaction?

49. Redox reactions involve the transfer of energy and _________ between atoms.

50. What happens during oxidation?

51. What happens during reduction?

52. Give an example of oxidation.

53. Give an example of reduction.

Section 2-3        Solutions   

54. Many of the chemical reactions in organisms take place in __________.

55. What is a solution?

56. Give an example of a complex solution in your body.

57. Name & describe the 2 parts of a solution.

58. What is meant by concentration of the solution?

59. How do you get a saturated solution?

60. What are aqueous solutions?

61. Explain dissociation of water molecules.

62. Name and give the charge for the 2 ions formed whenever water dissociates.

63. Write the final equation for the dissociation of water.

64. What is the hydronium ion?

65. How are acidity and alkalinity measured?

66. When would a solution be neutral?    Give an example of a neutral solution.

67. When would solutions be considered as acidic?

68. Acids have what taste?

69. Acids form what ion in water?

70. Give an example of an acid in your stomach.

71. When would solutions be considered as a base?

72. What adjective refers to basic solutions?

73. Give an example of a base.

74. What ion forms whenever a base is dissolved in water?

75. How does a base taste and feel?

76. How is soap made?

77. What is the pH scale used for?

78. What is the range for the pH scale?

79. At what pH would you find each of these solutions on a pH scale:    a. acids?    b. Bases?    c. neutral?

80. How many times stronger is a pH of 3 than a pH of 5?

81. A change of one pH unit reflects a __________ change.

82. Why is controlling the pH range important to organisms?

83. How do organisms control their pH levels?

84. What is a buffer?

85. Give an example of a human body fluid that is:    a. acidic?    b. alkaline?


BACK

Chapter 2 – Chemistry Outline

 

Student Name
Date
Period
Chapter 2        Chemistry Outline
I. Composition of Matter
         A. Matter
  * 1.1  1. Makes up everything
             2. Occupies space & has mass
             3. Mass – quantity of matter making up an object
             4. Pull of gravity produces weight
             5. Chemical changes in matter necessary for life processes
   B. Elements and Atoms
           1. Pure substances that can’t be chemically broken down
           2. about 30 elements important to organisms
           3. Most common elements are C, H, O, N
           4. Symbols (1-2 letters) stand for elements
             5. May use Latin or Greek  e.g. Na – sodium (natrium)
*1.2 6. Simplest part of an element with the same properties
                                
 C. Nucleus
           1.  Most of the mass
           2. Central part of an atom
           3.

Chemistry Powerpoint Worksheet

Chemistry PowerPoint Notes  

1. What makes up everything in the universe?  

2. Name 2 properties of all matter.  

 

3. Define mass.  

 

4. How does weight differ from mass?  

 

5.What are elements?  

 

6. Name the 4 elements that make up most of a living thing.  

 

7. What is used to represent an element?  

8. Name the smallest part of an element.  

9. What are the 2 main regions of an atom?  

10. Where is the nucleus of an atom found and what does it contain?  

11. What is the charge on a proton?              A neutron?  

12. All atoms of the same element have the ________ number of protons.  

13. The number of protons in an atom determines the _________________________.  

14. What is the charge on an electron?  

15. If you know the number of protons in an atom, how can you determine the number of electrons?  

 

16. Do all the atoms of the same element have the same number of neutrons?  

17. Atoms of the same element with different numbers of neutrons are called ___________.  

18. The mass of an atom is centered in the ___________.  

19. The number of protons PLUS neutrons in an atom determines its ___________________.  

20. What atomic particle has a negative charge?  

21. Why isn’t the mass of an electron used to determine the atomic mass of an element?  

 

22. Where are electrons found?

23. Which electrons in an atom have the most energy?  

24. How many energy levels are there & name them?  

25. How many electrons will each energy level hold?  

 

26. Elements are arranged on a __________________ by their atomic _____________.  

27. What are Periods & what do they tell you about elements?  

 

28.What are Families & what do they tell you about elements?  

 

29. Two or more elements combined together make a _____________.  

30. Chemical ______________ represent compounds.  

31. _____________ are the smallest part of a compound.  

32. ______________ in chemical formulas tell the number of atoms of each element.  

33. _____________ in a formula tell the number of molecules.  

34. Compounds have ____________ properties than its elements.  

35.  The outermost _______________ in elements determine if they will combine.  

36. Elements with ___________ outer energy levels are stable & won’t react.  

37. Why do elements tend to react with other elements?  

 

38. Chemical _____________ represent chemical reactions.  

39. ______________ appear on the right of the equation, while ___________ are on the left.  

40. Chemical bonds store ____________.  

41. How do covalent bonds form?

 

42. How do ions form?

 

43. Positive ions _________ electrons, while negative ions ___________ electrons.  

44.  Define energy.  

 

43. Give some examples of different forms of energy.  

44. Atoms are in constant ________________, which determines the atom’s ____________.  

45.  List the 3 main states of matter.  

46. _______________ energy must be added or removed to change the state of matter.  

47. In reactions the amount of product must ____________ the amount of reactants.  

48. Most of an organism’s energy comes from _____________ in foods.  

49. _______________ reactions release energy.  

50. Give an example of an exergonic reaction in cells.  

51. _________________ reactions store energy.  

52.  Give an example of an endergonic reaction in cells.  

53. Most reactions in cells are _________________.  

54.  _________________ energy is the energy needed to start a reaction.  

55. Catalysts _____________ the amount of activation energy needed.  

56. Catalysts in organisms are called ______________ and are usually ______________.  

57. Enzymes act on ____________ which join at the _______________ site.  

58. Can enzymes be reused?  

59. Redox reactions stands for _________________________ reactions.  

60. The oxidized substance _____________ electrons & becomes _____________ charged.  

61. The reduced substance _____________ electrons & becomes _____________ charged.  

62. Define solution.

 

63. The _____________ is dissolved in the ____________ in a solution.  

64. _______________ is the universal solvent.  

65. A solution becomes _____________ when no more solute will dissolve.  

66. ______________ solutions have water as the solvent & are important to ______________.  

67. What is the dissociation of water?

 

68. Write the equation for this.

 

69.  OH is the ______________ ion, while H+ is the ______________ ion.  

70. Acids produce _____________ ions, while bases have an excess of ________ ions.  

71. The _______ scale measures the concentration of H+ ions and goes from ____________.  

72. From 0 to 7 are ___________, a pH of 7 is __________, & above 7 to 14 are _________.  

73. _____________ are used in the body to control pH and keep it near a pH of ______ or neutral.  

 

Catalase Bi Sample Lab 2

 

 

Enzyme Rate of Reaction for Catalase

 

Introduction:
Life would not be possible without chemical reactions. Chemical reactions are responsible for speeding up the process. A chemical reaction is the process of breaking chemical bonds, forming new bonds or both. The four things that can speed up a chemical reaction is heat, increasing the concentration of reactants, decreasing the concentration of products, and enzymes. Enzyme is a catalase, most the time a protein. Enzymes can control the rate of a reaction, and they also lower activation energy. Enzymes are important in regulating chemical pathways, synthesizing materials needed by cells, releasing energy, and transferring information. Enzymes are involved in digestion, respiration, vision, movement, and thought. There are several things that can affect the function of enzymes like temperature, the pH, and the amount of reactant or product. Simple cells may have as many as 2000 different enzymes, each one catalyzing a different reaction. In this particular lab, your hands act as the enzyme “Catalase”. This enzyme, which is found in your cells, splits hydrogen peroxide, a byproduct made by your cells during cellular respiration,  into water and oxygen.

 

Hypothesis:
If  time is increased, then more hydrogen peroxide molecules will be split into water and oxygen

 

Materials:
The materials used in this lab were pencils, scissors, envelope, 100 paper hydrogen peroxide molecules, and a watch with a second hand so that a person would be able to keep time for the person tearing the strips.

 

Methods:
Take a paper template and cut out 100 hydrogen peroxide molecules. Place the cut out pieces into an envelope. Then have a person act as a catalase and take one piece of the paper molecules out of the envelope at a time and rip it in two and  place the pieces back into the envelope. Have a person hold the envelope person, while another student keeps track of the “tearing” time intervals (10, 20, 30 ,60, and 60 seconds). Count how many molecules are  ripped at the end of each time interval and record this number in your data table. When all time intervals and counts are completed, use the formula below to figure the reaction rate for catalase. Record this rate in  your data table.
M2 – M1 = reaction rate
T2 – T1

Results:

 

 

Time in seconds

 

Ripped Hydrogen Peroxide Molecules

 

Rate of reaction

 

0-10

3.3
 

10-30

10.35
 

30-60

24.47
 

60-120

63.65
 

120-180

1241.02

 

1. What is an enzyme? What are its functions in living things?
Enzymes are proteins in living systems. Enzymes can control the rate of a reaction, and they lower activation energy.

 

2. Name several things things that can affect the function of an enzyme?
Temperature, the amount of reactant or product and the pH.

3. Write the chemical equation for the breakdown of hydrogen peroxide by the enzyme catalase.
hydrogen peroxide + catalase yields water + oxygen

4. An enzyme’s efficiency increases with greater substrate concentration, but only up to a point. Why?
all of the active sites of the enzymes become filled with hydrogen peroxide molecules

 

5. If you were allowed to continue this lab and rip hydrogen peroxide molecules for 240 and 300 seconds. What would happen to the rate of reaction and why would this happen?
It would increase.

 

6. What can you say about the length of time and the rate of the reaction?
The less time, the more the reaction rate is lowered, and the more time, the more the reaction rate is higher.

 

7. What would happen to the rate of reaction if you remove the water  and oxygen molecules as soon as they are produced?
It would be faster.

 

Error Analysis:
All pieces must be returned to the envelope each time interval to correctly simulate what occurs within a cell.

 

Discussion and Conclusion:
As the time intervals increased, the reaction rate of catalase increased also. In a living cell, more hydrogen peroxide would be broken down by catalase over a longer period of time.

Catalase Lab Sample 1

 

 

Enzyme Rate of Reaction for Catalase

 

Introduction:
Enzymes are an important part of life that regulate chemical reactions with in the body. Enzymes speed up chemical reactions in four different ways, one way is heat, another is increasing the rate of reactants, the third way is decreasing the amount of products and the fourth way is enzymes, which speed up reaction without themselves being used up. Enzymes are also involved in digestion, respiration, reproduction, vision, movement, thought, and also in the productions of other enzymes. Simple cells may have as many as 2000 enzymes with each one catalyzing a different reaction. An enzyme can speed up a reaction making it 10, 000,000,000 times faster. An enzyme is a catalyst. A catalyst is a chemical that reduces the amount of activation interim needed for a reaction. Without enzymes a reaction would take much longer than if it had and enzyme. Enzymes also the control the rate and direction of the reaction.
Without catalysts chemical reactions would take much longer that the average human life expectancy. So that would mean that in 76 years only a couple chemical reactions would take place. Since our bodies have enzymes though hundreds of chemical reactions a day. If our bodies didn’t have catalysts our bodily cells couldn’t function. Some bacteria, however, possess a defense mechanism which can minimize the harm done by the two compounds. These resistant bacteria use two enzymes to catalyze the conversion of hydrogen peroxide  back into diatomic oxygen and water. One of these enzymes is catalase and its presence can be detected by a simple test. The catalase test involves adding hydrogen peroxide to a cultures sample or an agar slant.

 

Hypothesis:
The reaction rate of catalase splitting hydrogen peroxide into water and oxygen will increase over time.

Materials:
The materials used consisted of 100 paper H2O2 molecules, a data table, paper, pencil, calculator, scissors, watch with a second hand, and an enzyme rate of reaction catalase worksheet.

Methods:
Cut out 100 hydrogen peroxide paper molecules. Double check to make sure there are only 100 paper molecules and place them in an envelope. Then one person will keep track of the time while another person acts as a catalase and tears the paper hydrogen peroxide molecules in half. The torn paper molecules should be returned to the envelope each time. Another person times the person acting as the catalase.  The time intervals in which the paper molecules are to be ripped are 10 seconds, 20 seconds, 30 seconds, and two different 60second periods of time. The results should be  recorded in a data table. The reaction rate for catalase is figured using the formula:
M2 – M1 = Reaction Rate
T2  –  T1

 

Results:

 

 

Time in Seconds Ripped H2O2 MoleculesRate of Reaction
0-105.5
10-3013.4
30-6031.6
60-12061.5
120-18091.5

 

1. What is an enzyme? What are its functions in living things?
chemicals that reduce the amount of activation energy needed for reactions to occur; they are proteins in cells that control metabolic reactions

 

2. Name several things that can affect the functioning of an enzyme.
temperature, pH, and the amount of reactant or product

 

3. Write the chemical equation for the breakdown of hydrogen peroxide by the enzyme catalase.
H2O2   +   Catalase –>  H2O  + O2

 

4. An enzyme’s efficiency increases with greater substrate concentration, but only up to a point. Why?
once all active sites are filled, the enzyme’s reaction rate won’t continue increasing

 

5. If you were allowed to continue this lab and rip hydrogen peroxide molecules for 240 and 300 seconds, what would happen to the reaction rate and why would this happen?
there would be more molecules ripped because of the increased amount of time

 

6. What can you say about the length of time and the reaction rate?
The more time available, the faster the reaction will occur.

 

7. What would happen to the reaction rate if you removed the water and oxygen molecules as soon as they were produced?
The rate of reaction would go even faster

 

Error Analysis:
The counting of the time  may have been off a couple of seconds.

 

Discussion and Conclusion:
The data shows that the more time there is, the more hydrogen peroxide molecules will be ripped. The catalase in the lab ripped about 6 molecules every 5 seconds. The same thing occurs in a cell as more hydrogen peroxide is produced, catalase speeds up breaking down this waste into water and oxygen.