Download Part 1 - Human Organization

PART I
HUMAN ORGANIZATION
2
Chemistry of Life
3
Cell Structure and Function
4
Organization and Regulation of Body Systems
Chapter 2-Chemistry of Life
BEHAVIORAL OBJECTIVES
1. List the elements most commonly found in living things. [2.1, p.16]
2. Indicate the relationship between elements and atoms. [2.1, pp.16-17]
3. Describe the structure of an atom, stating the location, mass, and charge of protons, neutrons, and electrons.
[2.1, pp.16-17, Fig. 2.2a, and 2.2b]
4. Describe an electrically neutral atom. [2.1, pp.16-17, Fig. 2.2, and 2.2b]
5. Explain the nature of isotopes and radioactive isotopes. [2.1, p.17]
6. Describe the nature of a molecule. [2.2, pp.18-20, Fig. 2.4, 2.5, and 2.6]
7. Indicate the relationship between compounds and molecules [2.2, pp.19-20]
8. Describe what happens to the electrons when atoms change into ions. [2.2, p.18, Fig. 2.4, Table 2.1]
9. Understand the nature of covalent bonds. [2.2, p.20, Fig. 2.6]
10. List the important properties of water molecules. [2.3, pp.21-22, Fig. 2.7 and 2.8]
11. Discuss the general chemical properties of acids and bases. [2.3, p.23, Fig. 2.9, 2.10 and 2.11]
12. Explain and be able to use the pH scale. [2.3, pp.24-25, Fig. 2.12]
13. Explain the biological significance of buffers. [2.3, p. 24]
14. Describe the basic composition of organic molecules. [2.4, p.26; Table 2.3 on p. 38]
15. Explain the formation of polymers by dehydration synthesis and their breakdown by hydrolysis. [2.4, p.26, Fig.
2.17, 2.20, and 2.24]
16. Describe the structure and function of carbohydrates. [2.5, pp.27-28, Fig. 2.16, 2.17, 2.18, and 2.19]
17. Describe the function and the structure of lipids, emulsifiers, phospholipids, and steroids. [2.6, pp.29-30,
Fig.2.20, 2.21, and 2.22]
18. Recognize the difference between saturated and unsaturated fatty acids. [2.6, p.29, Fig. 2.20]
19. Describe the functions and basic structure of proteins. [2.7, pp.31-33, Fig. 2.23, 2.24, and 2.25]
20. Compare the primary, secondary, tertiary, and quaternary structures of proteins. [2.7, pp.32-33, Fig. 2.25]
21. Discuss the structure of nucleic acids, and describe their functions in cells. [2.8, pp.35-36, Fig. 2.26, Table 2.2]
22. Describe the structure and function of ATP. [2.8, p.35, Fig. 2.27]
23. Understand and use the bold-faced and italicized terms included in this chapter. [Understanding Key Terms,
p.39]
EXTENDED LECTURE OUTLINE
2.1 Elements and Atoms
Atoms
Matter is composed of atoms that contain the subatomic particles. The atomic number is equal to the number of
protons and therefore the number of electrons in an electrically neutral atom.
Isotopes
The atomic weight equals the number of protons plus the number of neutrons. Isotopes are atoms that have the same
atomic number but differ in the number of neutrons. Most isotopes are stable but some emit radiation.
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Image 00011l.jpg (Fig. 2.1)
Image 0012al.jpg (Fig. 2.2a)
Image 0012bl.jpg (Fig. 2.2b)
Image 0013l.jpg (Fig. TA2.1)
Life Science Animations VRL 2.0
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Image 0014l.jpg (Fig. 2.3)
Introduction/General Chemistry/Atomic Structure
Introduction/General Chemistry/Model of Helium (He)
Cells/Chemistry/Atoms
Case Studies Online
Radioactive Wastes From Medical Facilities: Where Do They
Go?
Transparencies
7 (Fig. 2.2a)
8 (Fig. 2.2b)
9 (Fig. 2.3b)
2.2 Molecules and Compounds
Ionic Reactions
During an ionic reaction, certain atoms give up and others receive electrons to achieve a stable outer shell that
contains eight electrons. The resulting oppositely-charged ions (charged particles) are attracted to each other
forming thereby an ionic bond.
Covalent Reactions
Following a covalent reaction, atoms share pairs of electrons within a covalent bond in order to achieve a stable
outer shell.
Double and Triple Bonds
In a double bond, atoms are sharing two pairs of electrons and in a triple bond they are sharing three pairs
of electrons.
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Image 0015al.jpg (Fig. 2.4a)
Image 0015bl.jpg (Fig. 2.4b)
Image 0015cl.jpg (Fig. 2.4c)
Image 0015dl.jpg (Fig. 2.4d)
Image 0015el.jpg (Fig. 2.4e)
Image 0016l.jpg (Fig. 2.5)
Image 0017al.jpg (Fig. 2.6 – water)
Image 0017bl.jpg (Fig. 2.6 – nitrogen gas)
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Introduction/General Chemistry/Covalent Bond
Introduction/General Chemistry/Ionic Bond
Introduction/General Chemistry/Ionic Reaction
Cells/Chemistry/Bonds
Transparencies
10 (Fig. 2.4)
Life Science Animations VRL 2.0
11 (Fig. 2.5)
12 (Fig. 2.6)
2.3 Water and Living Things
Life as we know it would be impossible without water which comprises about 70% of the cell. Water molecules are
polar and bonded to one another by hydrogen bonds.
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Properties of Water
Due to its polarity and/or hydrogen bonding, water is a liquid at room temperature; is the universal solvent; fills
vessels; loses and gains heat slowly; has a high heat of vaporization; and is less dense when frozen. These properties
are necessary to life.
Acidic and Basic Solutions
Water dissociates into an equal number of hydrogen and hydroxide ions.
Acidic Solutions
Acids release hydrogen ions. Compared to water, acidic solutions have more hydrogen ions than hydroxide
ions.
Basic Solutions
Bases take up hydrogen ions or release hydroxide ions. Compared to water, basic solutions have more
hydroxide ions than hydrogen ions.
The Litmus Test
A simple laboratory litmus test is used to tell when a solution is acidic or basic.
The pH Scale
The pH scale is a method to indicate the acidity or basicity of a solution. Acids have a pH lower than 7 and bases
have a pH higher than 7.
Buffers and pH
Buffers are molecules that resist pH changes and help maintain the pH at normal level in body fluids.
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Image 0018l.jpg (Fig. 2.7)
Image 0019l.jpg (Fig. TA2.2)
Image 0020l.jpg (Fig. TA2.3)
Image 0021l.jpg (Fig. 2.8)
Image 0022l.jpg (Fig. 2.9)
Image 0023l.jpg (Fig. 2.10)
Image 0024l.jpg (Fig. 2.11)
Image 0025l.jpg (Fig. TA2.4)
Image 0026al.jpg (Fig. 2.12)
Image 0026bl.jpg (Fig. 2.12)
Image 0026cl.jpg (Fig. 2.12)
Image 0027l.jpg (Fig. TA2.5)
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Image 00281.jpg (Fig. 2A)
Introduction/General Chemistry/Water Molecule
Introduction/General Chemistry/Water as a Transport Medium
Cells/Chemistry/Water
Cells/Chemistry/pH
Case Studies Online
Personal Watercraft Pollute Air and Water; Restrictions
Proposed
Transparencies
13 (Fig. 2.7)
14 (Fig. TA2.1-TA2.2)
15 (Fig. 2.9)
16 (Fig. 2.10)
17 (Fig. 2.11)
18 (Fig. 2.12)
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2.4 Molecules of Life
Organic molecules which contain carbon and hydrogen are varied and often large because carbon can share with any
many as four other atoms including other carbon atoms. Carbon chains often end with a functional group that gives
the chain particular properties and determines whether the molecule is hydrophobic or hydrophilic.
Large organic molecules (macromolecules) are often polymers which are formed when monomers join together.
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Image 0029l.jpg (Fig. TA2.6)
Image 0030l.jpg (Fig. TA2.7)
Image 0031l.jpg (Fig. TA2.8)
Image 0032l.jpg (Fig. TA2.9)
Image 0033l.jpg (Fig. TA2.10)
Image 0034l.jpg (Fig. 2.13)
Image 0035l.jpg (Fig. 2.14)
Image 0036l.jpg (Fig. 2.15)
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Introduction/Macromolecule/Condensation Synthesis and
Hydrolysis of Polymers
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Cells/Chemistry/Organic Chemistry
2.5 Carbohydrates
Contain the grouping H—C—OH in which the ratio of hydrogen atoms to oxygen is the same as water. Disaccharide
formation and break down typifies how larger organic molecules are formed. During condensation, synthesis
monomers join as water is removed and during hydrolysis, the monomers separate as water is added.
Simple Carbohydrates
Monosaccharides have a low number of carbon atoms; a pentose has five carbon atoms and a hexose has six carbon
atoms. Glucose, a hexose that is commonly called blood sugar, provides a ready source of energy for cells.
Starch and Glycogen
Polysaccharides such as starch (fewer side branches) and glycogen are polymers of glucose molecules.
Cellulose
Cellulose, a polysaccharide found in plant cell walls is commonly called fiber. The linkages joining glucose units
cannot be digested and therefore cellulose adds bulk that aids elimination.
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Image 0037l.jpg (Fig. 2.16)
Image 0038l.jpg (Fig. 2.17)
Image 0039l.jpg (Fig. TA2.11)
Image 0040l.jpg (Fig. 2.18)
Image 0041l.jpg (Fig. 2.19)
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Cells/Chemistry/Carbohydrates
Transparencies
19 (Fig. 2.16)
20 (Fig. 2.17)
21 (Fig. 2.18)
22 (Fig. 2.19)
2.6 Lipids
Lipids are hydrophobic and do not dissolve in water.
Fats and Oils
Solid fats of animal origin and liquid oils of plant origin are both composed of glycerol bonded to three fatty acids.
Fats and oils are a long-term energy source for organisms.
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Saturated and Unsaturated Fatty Acids
Saturated fatty acids have no double bonds and unsaturated fatty acids do have double bonds between
carbon atoms.
Emulsifierss
Emulsifiers cause fat droplets to disperse in water because a nonpolar end projects into a fat droplet, and a polar end
projects outward to interact with water.
Phospholipids
Phospholipids which have a polar phosphate group instead of a third fatty acid are the primary constituent of the
plasma membrane bilayer. The nonpolar tails face one another and the polar ends face the external environment.
Steroids
Steroid molecules have a backbone of four fused carbon rings that different according to their functional groups.
Cholesterol and the sex hormones are steroids.
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Image 0042l.jpg (Fig. 2.20)
Image 0043l.jpg (Fig. TA2.12)
Image 0044al.jpg (Fig. 2.21)
Image 0044bl.jpg (Fig. 2.21)
Image 0045l.jpg (Fig. 2.22)
Life Science Animations VRL 2.0
Introduction/Macromolecule/Phospholipid Structure and Shape
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Cells/Chemistry/Lipids
Transparencies
23 (Fig. 2.20)
24 (Fig. TA2.3)
25 (Fig. 2.21)
26 (Fig. 2.22)
2.7 Proteins
Proteins contain one to several polypeptides, each a polymer of amino acids. An amino acid contains an amine
group, an acid group, and an R (remainder) group that distinguishes the twenty different amino acids in cells.
Peptides
Amino acids are joined by a linkage called a peptide bond. A polypeptide is a single chain of amino acids.
Levels of Protein Organization
The primary structure of a polypeptide is the sequence of amino acids. The secondary structure is often an alpha
helix; the tertiary shape is due to interactions between the R groups; and a quaternary structure occurs if there is
more than one polypeptide.
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Image 0046al.jpg (Fig. 2.23)
Image 0046bl.jpg (Fig. 2.23)
Image 0047l.jpg (Fig. 2.24)
Image 0048l.jpg (Fig. TA2.13)
Image 0049al.jpg (Fig. 2.25)
Image 0049bl.jpg (Fig. 2.25)
Image 0049cl.jpg (Fig. 2.25)
Image 0049dl.jpg (Fig. 2.25)
Image 0050l.jpg (Fig. 2B)
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Introduction/Macromolecule/Levels of Protein Organization
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Cells/Chemistry/Proteins
Case Studies Online
Golden Rice Is Life
Transparencies
27 (Fig. 2.23)
28 (Fig. 2.24)
29 (Fig. 2.25)
30 (Fig. 2B)
2.8 Nucleic Acids
DNA and RNA are polymers of nucleotides. A nucleotide contains phosphate , a pentose sugar, and a nitrogencontaining base. The bases in DNA are adenine, thymine, cytosine, and guanine. In RNA, uracil replaces thymine.
DNA is a double helix—if unwound its structure resembles a stepladder. Phosphate and glucose makes up the sides
of the ladder and the hydrogen bonded bases are the rungs. DNA makes up the genes and RNA is an intermediary
during the process of protein synthesis.
ATP (Adenosine Triphosphate)
ATP is a nucleotide that contains three phosphate groups. ATP is a high energy molecule that releases energy when
a phosphate group is removed and the molecule becomes ADP. ATP is the energy currency of cells. When cells
require energy they spend ATP molecules.
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Image 0051l.jpg (Fig. TA2.14)
Image 0052al.jpg (Fig. 2.26)
Image 0052bl.jpg (Fig. 2.26)
Image 0053l.jpg (Fig. 2.27)
Image 0054l.jpg (Fig. 2C)
Image 0055l.jpg (Fig. TA2.15)
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Principles of Inheritance/DNA Genetic Material/DNA Structure
Cell/Energy and Enzymes/The ATP Cycle
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Cells/Chemistry/Nucleic Acids
Transparencies
31 (Fig. TA2.4)
32 (Fig. 2.26)
33 (Fig. 2.27)
34 (Fig. TA2.5)
SEVENTH EDITION CHANGES
New/Revised Text:
This was chapter 1 in the previous edition.
2.6 Lipids. The discussion of soap was replaced by a discussion of emulsifiers.
New Bioethical Focus: Organic Pollutants
New/Revised Figures:
2.12 The pH scale; 2.18 Glycogen structure and function
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STUDENT ACTIVITIES
pH Measurements
1. Students should read the Ecology Focus, "The Harm Done by Acid Deposition," before coming to class. They
should also collect and bring in water samples from their dorm faucets, drinking fountains, rainwater, or a
nearby pond or stream. Have pH paper or a pH meter available in class to determine the pH of these samples.
Discuss the known or potential effects of acid rain in your particular geographic location, which might include:
effects on forests, including interruption of the symbiotic association between trees and their mycorrhizae,
depletion of fisheries in lakes, or deterioration of car finishes and statues.
What are you eating?
2. Ask students to read the Health Focus, “Nutrition” on p. 34 before coming to class. Have students keep track of
what they have eaten the day before class, and during class ask students to categorize foods as carbohydrate,
protein, or lipid. This discussion helps students make the connection between types of organic molecules and
their functions in the diet and in cells.
Are You Drinking Organic Pollutants?
3. Read the Bioethical Focus “Organic Pollutants” to students during class. Bring along water samples from local
wells, fill a few small paper cups, and ask whether students are willing to drink the well water without knowing
what contaminants it contains. Determine how a local landowner might have well water samples tested for
organic pollutants and determine the cost of this type of testing (it is generally quite expensive). Share this
information with your students and ask them whether the local, state, or national government should pay for
such testing using tax dollars. In addition, ask “should all people, rich or poor, have access to safe drinking
water?”
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