Biochemistry Worksheet

        Section 3.1 - Properties of Water  

1. Why is water such an important molecule to living things?


2. Describe the chemical make up and type of bonding found in water molecules.


3. Explain why the hydrogen and oxygen atoms don't share electrons equally in a water molecule.


4. What is the effect of this uneven sharing of electrons in water?


5. Sketch a molecule of water showing the charges on the molecule.



6. What is the overall charge on a water molecule? Explain why.



7. Define polar compound and give an example.


8. Water's polarity makes it very effective in _____________ other substances.

9. Name 2 types of compounds that dissolve well in water.

10. What happens when an ionic compound such as sodium chloride (table salt) dissolves in water?


11. Water molecules are ___________ to other water molecules.

12. What type of bonding holds 2 or more water molecules together?

13. Are hydrogen bonds strong or weak bonds? Can they be easily broken?

14. Water molecules attracting other water molecules is called _________________.

15. Cohesion of water molecules produces ________________ tension making water seem like it has a "skin" on it. Surface tension enables some _____________ to walk across the surface of the water.

16. Water molecules attracting other types of molecules is called _________________.

17. Adhesion and cohesion together enable water molecules to move ____________ through narrow tubes against the force of gravity.

18. The above property of water is called _________________.

19. Give an example of an organism using capillarity.


20. What must be true for water to change temperature?

 21. What effect does heating water have on the hydrogen bonds holding the water molecules together? What happens to the speed at which the molecules are moving?


22. Give an example of how this water property helps organisms in the environment.


Section 3.2 - Carbon Compounds

23.  What is an organic compound?


24. Besides carbon, name 3 other elements that make up most organic compounds.

25. Carbon dioxide, CO2, is NOT an organic compound. Explain why


26. How many electrons are in the outermost energy level of carbon? How many does it need to have this energy level filled?

27. How many covalent bonds can carbon form?

28. Name 3 structural shapes that form whenever carbon atoms bond to other carbon atoms.


29. How many electrons are being shared in a single covalent bond? double covalent bond? triple covalent bond? quadruple covalent bond? 


30. Draw these 3 molecules and circle a single bond, double bond, and a triple bond in your drawings --- benzene, acetylene, and ethanol.



31. Explain what is meant by a functional group, & tell what effect they have on the molecules they are attached to.


32. Write the formula for these functional groups (use your textbook & handout) --- hydroxyl, carboxyl, phosphate group, amino group, and methyl group.



33. Hydroxyl groups attached to carbon atoms forms an _____________. Name an alcohol used in humans to assemble molecules needed for life.

34. Large carbon molecules are built from smaller, simpler molecules called ____________.

35. Large carbon molecules made of monomers are called _______________.

36. What are large polymers called?

37. What type of reaction links monomers to make polymers?

38. Sketch a molecule of sucrose (table sugar) formed from condensation. Name the 2 sugars that were combined to form sucrose.



39. Condensation reactions involve the removal of a molecule of ____________.

40. What reaction is used to breakdown polymers? Is water added or removed? How does this compare to condensation?


41. All life processes require a constant supply of ____________. Name the molecule used by cells to get energy. Give its abbreviation.

42. ATP contains what 3 functional groups covalently bonded together? Write the formula for this functional group.

43. Which bonded phosphate group on ATP releases the MOST energy when broken?

Section 3.3 - Macromolecules

44. Name the 4 main classes of macromolecules (organic molecules) & tell what 3 elements all of these contain.


Carbohydrates store energy for organisms!

45. In what ratio are hydrogen & oxygen atoms in carbohydrates?

46. In what 3 forms do carbohydrates exist?

47. What are the monomers of carbohydrates called? What is their common name? Give the ratio of carbons, hydrogens, & oxygens.

48. Name the 3 MOST common monosaccharides.

49. Sketch & label a molecule of each of these monosaccharides. How do they compare? Write the chemical formula for all three.




50. Because all 3 simple sugars have the same chemical, but different structural formulas, they are called _______________.

51. What are double sugars called? Name & describe the process that forms them.


52. Name a disaccharide.

53. What forms a polysaccharide? Name a polysaccharide found in animals. Name 2 found in plants?


54. What chemical reaction formed these large molecule? What reaction would be needed to break these molecules?


Proteins are used to build cells, & they act as enzymes!

55. What are the 4 main elements making up proteins? How many covalent bonds does each of these elements form?


56. Sketch these two amino acids --- glycine & alanine.  Circle the center carbon, place a triangle around the amino group, and put a box around the carboxyl group.






57. What are the monomers of proteins called? How many are there? Name the 4 things bonded to the center carbon of this monomer.



58. The main difference among amino acids is their ___________ group. What is the R-group on glycine? on alanine?

59. Differences in R-groups give different proteins different ______________.

60. How does a dipeptide form? Sketch the dipeptide formed from glycine and alanine. What molecule had to be removed to join these 2 amino acids?




61. What do you call the covalent bonds that hold amino acids together? Put a box around these bond in the sketch you did on question 60.

62. Long chains of amino acids are called ___________________ and these join together to make a ________________.

63. Hydrogen bonding among individual amino acids in a chain cause what effect on the protein's shape?

64, What is the effect of temperature on protein shape? Give an example of this.


65. Most proteins act as catalysts or __________________ inside of cells. 

66. The substance an enzyme is acting upon is called the _____________ and it must ______ into a place called the active site on the enzyme.

67. When a substrate joins with an enzyme, what effect does this have on chemical bonding of that substrate? Is the enzyme affected temporarily or permanently? How is it affected? 


68. When chemical bonds in a substrate are weakened, what effect does this have on activation energy needed to start the reaction?

69. After the reaction, what happens to the products? Can the enzyme be re-used & why?


70. Besides temperature, what else can effect how an enzyme works by changing the enzyme's shape? Can the reaction still take place?

Lipids include fats that are used for long-term energy storage!

71. Are lipids polar or nonpolar? What happens to lipids when they are placed in water?

72. Compared to carbohydrates, what is true about the ratio of carbon & hydrogen atoms to oxygen atoms? If a compound has more bonds, what can it store more of in those bonds?


73. Most lipids are made of ______________ acids. Describe their shape. What functional group is found on the head end of the molecule?


74. Sketch these 2 fatty acids --- palmitic & linoleic.  Circle the carboxyl group on the "head" of the molecule. Is this end polar or nonpolar? Will this end be attracted to  or repelled by water?






75. Are both ends of a fatty acid polar? Explain.

76. Hydophilic means water ___________. Which end of  a fatty acid is hydrophilic. The nonpolar end of a fatty acid is said to be _______________ or "water fearing".

77. Which end of a fatty acid chain WOULD dissolve in water? Which WOULDN'T?


78. In what type of fatty acid are there only single bonds in the carbon chain? Name one such fatty acid.

79. What type of bond appears in an unsaturated fatty acid? Give an example of an unsaturated fatty acid. Go back to your fatty acid drawings in question 74 and put a box around the double bond in the unsaturated fatty acid. 


80. Name the 3 groups of complex lipids.

81. What makes up a triglyceride? What is the difference between a saturated & unsaturated triglyceride?


82. What type of triglycerides tend to be solids at room temperature & why? Which are liquids & why?


83. What type of triglyceride would this of  substance be --- vegetable oil?  butter & shortening?

84. What makes up a phospholipid? How are they different from triglycerides? What main part of a cell is made of phospholipids?


85. What is meant by a lipid bilayer? What makes this such an effective barrier between the inside & the outside of the cell?


86. Wax is another complex lipid. Describe its structure.


87. Waxes are highly _________________. Explain how plants make use of this property? animals?


88. What makes up steroids? To what group of organic compounds do steroids belong? How are they used in animals?


89. Name a steroid made by the body & used by nerve cells.

Nucleic acids  store genetic information for cells!

90. Give the name & abbreviation for 2 nucleic acids found in cells.


91. DNA and RNA are both examples of _____________ made of linked monomers called ________________.  The instructions in these molecules is used to make ____________.

92. Name the 3 parts to a nucleotide then draw and label one.