CHAPTER 3 Macromolecules: Their Chemistry and Biology

Chapter 3: Macromolecules: Their Chemistry and Biology

CHAPTER 3Macromolecules: Their Chemistry and Biology


Chapter 3: Macromolecules: Their Chemistry and BiologyMacromolecules: Giant PolymersMacromolecules: Giant Polymers

Condensation ReactionsCondensation Reactions

Proteins: Polymers of Amino AcidsProteins: Polymers of Amino Acids

Carbohydrates: Sugars and Sugar Carbohydrates: Sugars and Sugar PolymersPolymers


Chapter 3: Macromolecules: Their Chemistry and BiologyNucleic Acids: Informational Nucleic Acids: Informational

MacromoleculesMacromolecules

Lipids: Water-Insoluble MoleculesLipids: Water-Insoluble Molecules

The Interactions of MacromoleculesThe Interactions of Macromolecules


Macromolecules: Giant Polymers• Macromolecules are formed by Macromolecules are formed by

covalent bonds between monomers covalent bonds between monomers and include polysaccharides, proteins, and include polysaccharides, proteins, and nucleic acids. and nucleic acids.

Review Figure 3.1 and Table Review Figure 3.1 and Table 3.13.1

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3.1

Figure 3.1Figure 3.1

figure 03-01.jpg


Table 3.1

Table 3.1Table 3.1

table 03-01.jpg


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 Monomers are joined by condensation reactions. reactions.

• Hydrolysis reactions break polymers Hydrolysis reactions break polymers into monomers. into monomers.

Review Figure 3.2Review Figure 3.2

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3.2


figure 03-02.jpg


Proteins: Polymers of Amino Acids• Functions of proteins include support, Functions of proteins include support,

protection, catalysis, transport, protection, catalysis, transport, defense, regulation, and movement. defense, regulation, and movement.

• They sometimes require an attached They sometimes require an attached prosthetic group. prosthetic group.

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Proteins: Polymers of Amino Acids

• Twenty amino acids are found in Twenty amino acids are found in proteins. proteins.

• Each consists of an amino group, a Each consists of an amino group, a carboxyl group, a hydrogen, and a side carboxyl group, a hydrogen, and a side chain bonded to the chain bonded to the carbon atom. carbon atom.

Review Table 3.2Review Table 3.2

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Table 3.2 – Part 1

Table 3.2 – Part 1Table 3.2 – Part 1

table 03-02a.jpg




table 03-02bc.jpg




table 03-02d.jpg



• Side chains of amino acids may be Side chains of amino acids may be charged, polar, or hydrophobic.charged, polar, or hydrophobic.

• SH groups can form disulfide bridges. SH groups can form disulfide bridges.

• Review Table 3.2 and Figure Review Table 3.2 and Figure 3.3 3.3

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3.3


figure 03-03.jpg



• Amino acids are covalently bonded Amino acids are covalently bonded together by peptide linkages. together by peptide linkages.

Review Figure Review Figure 3.4 3.4

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3.4


figure 03-04.jpg


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 3.520


Proteins: Polymers of Amino Acids• Secondary structures are maintained

by hydrogen bonds between atoms of the amino acid residues.

Review Figure 3.523


3.5 – Part 1

Figure 3.5 – Part 1Figure 3.5 – Part 1

figure 03-05a.jpg


Proteins: Polymers of Amino Acids• The tertiary structure is generated by

bending and folding of the polypeptide chain.

Review Figures 3.524


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, 3.725


3.5 – Part 2


figure 03-05b.jpg


3.7


figure 03-07.jpg



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

Review Figure 3.82727


3.8


figure 03-08.jpg



• Proteins denatured by heat, acid, or chemicals lose tertiary and secondary structure and biological function.

Review Figure 3.929


3.9


figure 03-09.jpg



• Chaperonins assist protein folding by preventing binding to inappropriate ligands.



3.10


figure 03-10.jpg


Carbohydrates: Sugars and Sugar Polymers

• All carbohydrates contain carbon bonded to H and OH groups.

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• Hexoses are monosaccharides that contain six carbon atoms.



3.11


figure 03-11.jpg


3.12 – Part 1


figure 03-12a.jpg


3.12 – Part 2


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• The pentoses are five-carbon monosaccharides.




• Glycosidic linkages may have either or orientation in space.

• They covalently link monosaccharides into larger units.



3.13


figure 03-13.jpg


3.14 – Part 1


figure 03-14a.jpg


3.14 – Part 2


figure 03-14b.jpg



• Cellulose, a polymer, is formed by glucose units linked by -glycosidic linkages between carbons 1 and 4.




• Starches are formed by -glycosidic linkages between carbons 1 and 4 and are distinguished by amount of branching through glycosidic bonds at carbon 6.




• Glycogen contains -1,4 glycosidic linkages and is highly branched.




• Chemically modified monosaccharides include the sugar phosphates and amino sugars.

• A derivative of the amino sugar glucosamine polymerizes to form the polysaccharide chitin.



3.15


figure 03-15.jpg


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 49


3.16


figure 03-16.jpg


Table 3.3

Table 3.3Table 3.3

table 03-03.jpg



• In the nucleic acids, bases extend from a sugar–phosphate 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.



3.17 – Part 1


figure 03-17a.jpg


3.17 – Part 2


figure 03-17b.jpg


3.18


figure 03-18.jpg



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



3.19


figure 03-19.jpg



• 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.



3.20


figure 03-20.jpg



• Phospholipids have a hydrophobic hydrocarbon “tail” and a hydrophilic phosphate “head.”

Review Figure 3.21 63


3.21


figure 03-21.jpg


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.



3.22


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Lipids: Water-Insoluble Molecules• Carotenoids trap light energy in green

plants. β-Carotene can be split to form vitamin A, a lipid vitamin.



3.23


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• 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.



3.24


figure 03-24.jpg



• 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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• Glycoproteins contain an oligosaccharide “label” that directs the protein to the proper cell destination.

• The carbohydrate groups of glycolipids are on the cell’s outer surface, serving as recognition signals.

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

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CHAPTER 3 Macromolecules: Their Chemistry and Biology

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