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CHAPTER 3 Macromolecules: Their Chemistry and Biology. 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 Macromolecules: Giant Polymers Condensation Reactions Proteins: Polymers of Amino Acids Carbohydrates: Sugars and Sugar Polymers
Chapter 3: Macromolecules: Their Chemistry and Biology Nucleic Acids: Informational Macromolecules Lipids: Water-Insoluble Molecules The Interactions of Macromolecules
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 4
figure 03-01.jpg 3.1 Figure 3.1
table 03-01.jpg Table 3.1 Table 3.1
Macromolecules: Giant Polymers • Macromolecules have specific three-dimensional shapes. • Different functional groups give local sites on macromolecules specific properties. 7
Condensation Reactions • Monomers are joined by condensation reactions. • Hydrolysis reactions break polymers into monomers. Review Figure 3.2 8
figure 03-02.jpg 3.2 Figure 3.2
Proteins: Polymers of Amino Acids • Functions of proteins include support, protection, catalysis, transport, defense, regulation, and movement. • They sometimes require an attached prosthetic group. 10
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 11
table 03-02a.jpg Table 3.2 – Part 1 Table 3.2 – Part 1
table 03-02bc.jpg Table 3.2 – Part 2 Table 3.2 – Part 2
table 03-02d.jpg Table 3.2 – Part 3 Table 3.2 – Part 3
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 15
figure 03-03.jpg 3.3 Figure 3.3
Proteins: Polymers of Amino Acids • Amino acids are covalently bonded together by peptide linkages. Review Figure 3.4 17
figure 03-04.jpg 3.4 Figure 3.4
Proteins: Polymers of Amino Acids • Polypeptide chains of proteins are folded into specific three-dimensional shapes. • Primary, secondary, tertiary, and quaternary structures are possible. 19
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 20
Proteins: Polymers of Amino Acids • Secondary structures are maintained by hydrogen bonds between atoms of the amino acid residues. Review Figure 3.5 23
figure 03-05a.jpg 3.5 – Part 1 Figure 3.5 – Part 1
Proteins: Polymers of Amino Acids • The tertiary structure is generated by bending and folding of the polypeptide chain. Review Figures 3.5 24
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. ReviewFigures 3.5, 3.7 25
figure 03-05b.jpg 3.5 – Part 2 Figure 3.5 – Part 2
figure 03-07.jpg 3.7 Figure 3.7
Proteins: Polymers of Amino Acids • Weak chemical interactions are important in the binding of proteins to other molecules. Review Figure 3.8 27
figure 03-08.jpg 3.8 Figure 3.8
Proteins: Polymers of Amino Acids • Proteins denatured by heat, acid, or chemicals lose tertiary and secondary structure and biological function. Review Figure 3.9 29
figure 03-09.jpg 3.9 Figure 3.9
Proteins: Polymers of Amino Acids • Chaperonins assist protein folding by preventing binding to inappropriate ligands. Review Figure 3.10 31
figure 03-10.jpg 3.10 Figure 3.10
Carbohydrates: Sugars and Sugar Polymers • All carbohydrates contain carbon bonded to H and OH groups. 33
Carbohydrates: Sugars and Sugar Polymers • Hexoses are monosaccharides that contain six carbon atoms. Review Figures 3.11, 3.12 34
figure 03-11.jpg 3.11 Figure 3.11
figure 03-12a.jpg 3.12 – Part 1 Figure 3.12 – Part 1
figure 03-12b.jpg 3.12 – Part 2 Figure 3.12 – Part 2
Carbohydrates: Sugars and Sugar Polymers • The pentoses are five-carbon monosaccharides. Review Figure 3.12 38
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 39
figure 03-13.jpg 3.13 Figure 3.13
figure 03-14a.jpg 3.14 – Part 1 Figure 3.14 – Part 1
figure 03-14b.jpg 3.14 – Part 2 Figure 3.14 – Part 2
Carbohydrates: Sugars and Sugar Polymers • Cellulose, a polymer, is formed by glucose units linked by β-glycosidic linkages between carbons 1 and 4. Review Figure 3.14 43
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 44
Carbohydrates: Sugars and Sugar Polymers • Glycogen contains a-1,4 glycosidic linkages and is highly branched. Review Figure 3.14 45
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 46
figure 03-15.jpg 3.15 Figure 3.15
Nucleic Acids: Informational Macromolecules • In cells, DNA is the hereditary material. DNA and RNA play roles in protein formation. 48
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
figure 03-16.jpg 3.16 Figure 3.16