Download Section 2-1: Nature of Matter

Ch. 2 The Chemistry of Life
Name __________________________
Per. ___________
California State Standard covered within this chapter:
Cell Biology
1. The fundamental life processes of plants and animals depend on a variety of chemical reactions
that occur in specialized areas of the organism's cells. As a basis for understanding this concept:
b. Students know enzymes are proteins that catalyze biochemical reactions without altering
the reaction equilibrium and the activities of enzymes depend on the temperature, ionic
conditions, and the pH of the surroundings.
h. Students know most macromolecules (polysaccharides, nucleic acids, proteins, lipids) in
cells and organisms are synthesized from a small collection of simple precursors.
Read the appropriate section in the textbook and look at the lecture notes before answering the following
questions. You must put all answers and definitions in your own words for full credit.
Section 2-1 The Nature of Matter
Define the following terms in your own words.
1. atom:
2. nucleus:
3. electron:
4. proton:
5. neutron:
6. Diagram and label the structure of an atom.
7. element:
The atomic number of an element is the number of protons in the atom. It is also the number of electrons.
The atomic mass is determined by adding together the mass of the protons and the mass of the neutrons.
Periodic Table of Elements
Use the Periodic Table of Elements above and in the back cover of your book to complete the following
table. Write the chemical symbol for each of the following elements.
Chemical Element
8. Oxygen
9. Carbon
10. Calcium
11. Hydrogen
Chemical Element
12. Nitrogen
13. Sodium
14. Chlorine
15. Phosphorus
Chemical Symbol
O
Chemical Symbol
It is most important to know what the subatomic particles are, where they are located in an atom, and that
atoms of different elements differ because they contain different numbers of protons. First, use the
Periodic Table of Elements above to fill in the number of protons, neutrons and electrons. Then sketch
each atom’s electron configuration, labeling and coloring protons red, neutrons gray, and electrons blue.
Element
Atomic
Number
16. Hydrogen
1
17. Carbon
18. Oxygen
Number Number Number
of
of
of
Electron Configuration
protons neutrons electrons
1
0
1
19. isotope:
20. radioactive isotope:
21. Describe two beneficial uses of radioactive isotopes.
22. chemical compound:
List 2 examples:
Describe the different kinds of chemical bonds.
Chemical Bond
Description
23. Ionic bond
24. Covalent bond
25. Polar covalent
bond (p. 40)
26. Hydrogen bond
(p. 41)
27. ion:
28. molecule:
29. matter:
Section 2-2: Properties of Water
Define the following terms in your own words.
30. cohesion:
31. adhesion:
32. mixture:
33. solution:
34. solute:
35. solvent:
36. Describe the properties of water that make it such an important substance for life. Use your lecture
notes to assist you in your description.
Property
Description
a. Heat capacity of water
b. Cohesion
c. Adhesion
d. “universal solvent”
e. Polarity of water
f. exists in all 3 states of
matter
g. solid form is less dense
than liquid
37. Name a substance that would not dissolve well in water. Explain why.
38. How might the fact that ice is less dense that liquid water be important to living things?
39. What does the pH scale actually measure?
40. Complete the table.
Proportion of ions
Acid
hydrogen
Contains more _________________
ions
Neutral
Contains _________________________
Base
Contains more _________________ ions
pH
range
Example
0-6.99
Hydrochloric
acid
Stomach acid
Note: A buffer maintains a stable pH in a solution. If there are too many H+ ions (because an acid is
added), the buffer will remove H+ ions from the solution. If there are too few H+ ions (because a base is
added), the buffer will add H+ ions to the solution.
Section 2-3: Chemistry of Cells
41. organic compounds:
42. Carbon has _____ electrons in its outer energy level. As such, carbon is _____ electrons short of
filling the outer energy level and being stable. Therefore, carbon readily forms four _____________
bonds with other elements.
43. monomers:
44. polymer:
Note:
• Polymers of living things are constructed from monomers by a series of reactions called condensation
reactions (dehydration reactions). These reactions result in covalent bonds between monomers.
• The reverse of a condensation reaction is a hydrolysis reaction. These reactions use water to break
apart polymers to produce monomers.
Biological Molecules
Carbohydrates
45. Carbohydrates can be found in three forms. Complete the following table be providing a description
and two examples of each form.
Form
Description
a. monosaccharide
b. disaccharide
c. polysaccharide
2 Examples for each
i. C6H12O6 – glucose
ii.
i.
ii.
i.
ii.
46. Sucrose is a disaccharide composed of ________________ and __________________, formed
through a __________________ reaction.
47. What is the primary function of carbohydrates?
Note: Carbohydrates readily dissolve in water and are said to be hydrophilic.
48. Describe the function of each of the following molecules.
Carbohydrate
Function
a. starch
b. glycogen
c. cellulose
Lipids
49. Unlike other organic compounds, lipids do not dissolve in ________________. As such, lipids are said
to be hydrophobic.
50. fatty acid:
51. Lipids come in a variety of forms which have different functions. Pay special attention to additional
information supplied to you in the table.
Form
a. Fat
Structure
Example
Function
Phosphate head
(hydrophilic) attached to 2
fatty acid tails
(hydrophobic)
Cell membrane
(phospholipid
bilayer)
Separates cell interior
from external
environment
b. Steroid
c. Phospholipid
52. Explain the difference between a saturated and an unsaturated fat.
53. How do lipids store energy efficiently?
Nucleic Acids
54. What is the monomeric unit for nucleic acids?
55. Draw the basic structure of a nucleotide and label the three different parts of the molecule.
56. Describe the function of the 2 forms of nucleic acids.
Form
a. DNA which stands for
Function
______________________________
b. RNA which stands for
______________________________
Proteins
57. amino acid:
58. Draw the basic structure of an amino acid and
label the major functional groups.
59. The covalent bond formed between a nitrogen atom and a carbon atom is called a
________________________.
60. Describe three functions of proteins.
61. Identify each of the levels of protein structure in the diagrams. Include a description of each structure
mentioning what type of bond(s) is/are responsible for each.
a. ____________________________
____________________________
b. ____________________________
____________________________
c. ____________________________
____________________________
d. ____________________________
____________________________
Study Tip: Make a Comparative Table for the Macromolecules. An example of some key headings might
be the following:
Type of
Functions of Polymeric
Monomeric Unit
Polymeric Forms
Macromolecule
Forms
Section 2-4: Chemical Reactions and Enzymes
62. chemical reaction:
63. Products are on the ____________ side of the equation.
64. Reactants are on the _____________ side of the equation.
65. potential energy:
66. kinetic energy:
Note: Chemical reactions either store or release energy
– Endergonic reactions—absorb and store energy in a reaction
– Exergonic reactions—energy is released from reaction
67. activation energy:
68. Draw energy profiles for the following types of reactions. Be sure to label them.
Exergonic (energy-releasing) reaction
Endergonic (energy-absorbing) reaction
69. Enzymes are proteins that act as ____________________, to speed up chemical reactions.
70. How does an enzyme speed up a chemical reaction?
71. Diagram a model of one of the ways scientists think that enzymes might work (Induced fit Model). Be
sure to label the steps of the model (p. 52).
72. Proteins are sensitive to their environment. Changes in pH, temperature, or other qualities can cause a
protein to denature. What does it mean for a protein to be denatured?
73. Why does a denatured protein no longer function?
74. Why do extreme high temperatures cause enzymes to denature?