Life, 6th Edition

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CHAPTER 3Macromolecules Their Chemistry and
Biology
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Chapter 3 Macromolecules Their Chemistry and
Biology

• Macromolecules Giant Polymers
• Condensation Reactions
• Proteins Polymers of Amino Acids
• Carbohydrates Sugars and Sugar Polymers

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Chapter 3 Macromolecules Their Chemistry and
Biology

• Nucleic Acids Informational Macromolecules
• Lipids Water-Insoluble Molecules
• The Interactions of Macromolecules

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Macromolecules Giant Polymers

• Macromolecules are formed by covalent bonds
  between monomers and include polysaccharides,
  proteins, and nucleic acids.
• Review Figure 3.1 and Table 3.1
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3.1
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• Figure 3.1

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Table 3.1
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• Table 3.1

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Macromolecules Giant Polymers

• Macromolecules have specific three-dimensional
  shapes.
• Different functional groups give local sites on
  macromolecules specific properties.
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Condensation Reactions

• Monomers are joined by condensation reactions.
• Hydrolysis reactions break polymers into
  monomers.
• Review Figure 3.2
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3.2
figure 03-02.jpg

• Figure 3.2

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Proteins Polymers of Amino Acids

• Functions of proteins include support,
  protection, catalysis, transport, defense,
  regulation, and movement.
• They sometimes require an attached prosthetic
  group.
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Proteins Polymers of Amino Acids

• Twenty amino acids are found in proteins.
• Each consists of an amino group, a carboxyl
  group, a hydrogen, and a side chain bonded to the
  a carbon atom.
• Review Table 3.2
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Table 3.2 Part 1
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• Table 3.2 Part 1

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Table 3.2 Part 2
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• Table 3.2 Part 2

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Table 3.2 Part 3
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• Table 3.2 Part 3

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Proteins Polymers of Amino Acids

• Side chains of amino acids may be charged, polar,
  or hydrophobic.
• SH groups can form disulfide bridges.
• Review Table 3.2 and Figure 3.3
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3.3
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• Figure 3.3

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Proteins Polymers of Amino Acids

• Amino acids are covalently bonded together by
  peptide linkages.
• Review Figure 3.4
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3.4
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• Figure 3.4

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Proteins Polymers of Amino Acids

• Polypeptide chains of proteins are folded into
  specific three-dimensional shapes.
• Primary, secondary, tertiary, and quaternary
  structures are possible.
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Proteins Polymers of Amino Acids

• The primary structure of a protein is the
  sequence of amino acids bonded by peptide
  linkages.
• Review Figure 3.5
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Proteins Polymers of Amino Acids

• Secondary structures are maintained by hydrogen
  bonds between atoms of the amino acid residues.
• Review Figure 3.5
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3.5 Part 1
figure 03-05a.jpg

• Figure 3.5 Part 1

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Proteins Polymers of Amino Acids

• The tertiary structure is generated by bending
  and folding of the polypeptide chain.
• Review Figures 3.5
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Proteins Polymers of Amino Acids

• The quaternary structure is the arrangement of
  polypeptides in a single functional unit
  consisting of more than one polypeptide subunit.
• Review Figures 3.5, 3.7
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3.5 Part 2
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• Figure 3.5 Part 2

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3.7
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• Figure 3.7

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Proteins Polymers of Amino Acids

• Weak chemical interactions are important in the
  binding of proteins to other molecules.
• Review Figure 3.8
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3.8
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• Figure 3.8

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Proteins Polymers of Amino Acids

• Proteins denatured by heat, acid, or chemicals
  lose tertiary and secondary structure and
  biological function.
• Review Figure 3.9
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3.9
figure 03-09.jpg

• Figure 3.9

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Proteins Polymers of Amino Acids

• Chaperonins assist protein folding by preventing
  binding to inappropriate ligands.
• Review Figure 3.10
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3.10
figure 03-10.jpg

• Figure 3.10

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Carbohydrates Sugars and Sugar Polymers

• All carbohydrates contain carbon bonded to H and
  OH groups.
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Carbohydrates Sugars and Sugar Polymers

• Hexoses are monosaccharides that contain six
  carbon atoms.
• Review Figures 3.11, 3.12
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3.11
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• Figure 3.11

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3.12 Part 1
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• Figure 3.12 Part 1

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3.12 Part 2
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• Figure 3.12 Part 2

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Carbohydrates Sugars and Sugar Polymers

• The pentoses are five-carbon monosaccharides.
• Review Figure 3.12
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Carbohydrates Sugars and Sugar Polymers

• Glycosidic linkages may have either a or b
  orientation in space.
• They covalently link monosaccharides into larger
  units.
• Review Figures 3.13, 3.14
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3.13
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• Figure 3.13

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3.14 Part 1
figure 03-14a.jpg

• Figure 3.14 Part 1

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3.14 Part 2
figure 03-14b.jpg

• Figure 3.14 Part 2

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Carbohydrates Sugars and Sugar Polymers

• Cellulose, a polymer, is formed by glucose units
  linked by ß-glycosidic linkages between carbons 1
  and 4.
• Review Figure 3.14
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Carbohydrates Sugars and Sugar Polymers

• Starches are formed by a-glycosidic linkages
  between carbons 1 and 4 and are distinguished by
  amount of branching through glycosidic bonds at
  carbon 6.
• Review Figure 3.14
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Carbohydrates Sugars and Sugar Polymers

• Glycogen contains a-1,4 glycosidic linkages and
  is highly branched.
• Review Figure 3.14
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Carbohydrates Sugars and Sugar Polymers

• Chemically modified monosaccharides include the
  sugar phosphates and amino sugars.
• A derivative of the amino sugar glucosamine
  polymerizes to form the polysaccharide chitin.
• Review Figure 3.15
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3.15
figure 03-15.jpg

• Figure 3.15

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Nucleic Acids Informational Macromolecules

• In cells, DNA is the hereditary material. DNA and
  RNA play roles in protein formation.
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Nucleic Acids Informational Macromolecules

• Nucleic acids are polymers of nucleotides
  consisting of a phosphate group, a sugar, and a
  nitrogen-containing base.
• The DNA bases are adenine, guanine, cytosine, and
  thymine.
• In RNA uracil substitutes for thymine.
• Review Figure 3.16 and Table 3.3
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3.16
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• Figure 3.16

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Table 3.3
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• Table 3.3

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Nucleic Acids Informational Macromolecules

• In the nucleic acids, bases extend from a
  sugarphosphate backbone.
• DNA and RNA information resides in their base
  sequences.
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Nucleic Acids Informational Macromolecules

• RNA is single-stranded.
• DNA is a double-stranded helix with
  complementary, hydrogen-bonded base pairing
  between adenine and thymine and guanine and
  cytosine.
• The two strands run in opposite directions.
• Review Figures 3.17, 3.18
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3.17 Part 1
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• Figure 3.17 Part 1

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3.17 Part 2
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• Figure 3.17 Part 2

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3.18
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• Figure 3.18

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Nucleic Acids Informational Macromolecules

• Comparing the DNA base sequences of different
  living species provides information on
  evolutionary relatedness.
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Lipids Water-Insoluble Molecules

• Lipids can form gigantic structures, but these
  aggregations are not chemically macromolecules
  because individual units are not linked by
  covalent bonds.
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Lipids Water-Insoluble Molecules

• Fats and oils are composed of three fatty acids
  covalently bonded to a glycerol molecule by ester
  linkages.
• Review Figure 3.19
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3.19
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• Figure 3.19

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Lipids Water-Insoluble Molecules

• Saturated fatty acids have a hydrocarbon chain
  with no double bonds.
• The hydrocarbon chains of unsaturated fatty acids
  have one or more double bonds that bend the
  chain, making close packing less possible.
• Review Figure 3.20
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3.20
figure 03-20.jpg

• Figure 3.20

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Lipids Water-Insoluble Molecules

• Phospholipids have a hydrophobic hydrocarbon
  tail and a hydrophilic phosphate head.
• Review Figure 3.21
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3.21
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• Figure 3.21

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Lipids Water-Insoluble Molecules

• In water, the interactions of the hydrophobic
  tails and hydrophilic heads generate a
  phospholipid bilayer two molecules thick.
• The head groups are directed outward, interacting
  with surrounding water.
• Tails are packed in the interior.
• Review Figure 3.22
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3.22
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• Figure 3.22

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Lipids Water-Insoluble Molecules

• Carotenoids trap light energy in green plants.
  ß-Carotene can be split to form vitamin A, a
  lipid vitamin.
• Review Figure 3.23
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3.23
figure 03-23.jpg

• Figure 3.23

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Lipids Water-Insoluble Molecules

• Some steroids function as hormones.
• Cholesterol is synthesized by the liver and has a
  role in some cell membranes, and in the digestion
  of other fats.
• Review Figure 3.24
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3.24
figure 03-24.jpg

• Figure 3.24

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Lipids Water-Insoluble Molecules

• Vitamins, required for normal functioning, must
  be acquired from the diet.
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The Interactions of Macromolecules

• Both covalent and noncovalent linkages are found
  between the various classes of macromolecules.
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The Interactions of Macromolecules

• Glycoproteins contain an oligosaccharide label
  that directs the protein to the proper cell
  destination.
• The carbohydrate groups of glycolipids are on the
  cells outer surface, serving as recognition
  signals.
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The Interactions of Macromolecules

• Hydrophobic interactions bind cholesterol to the
  protein that transports it in the blood.
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