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Lecture Biology (6e): Chapter 5 - Campbell, Reece

Chapter 5 - The structure and function of macromolecules. After reading this chapter and attending lecture, the student should be able to: List the four major classes of biomolecules, explain how organic polymers contribute to biological diversity, describe how covalent linkages are formed and broken in organic polymers,. | CHAPTER 5 THE STRUCTURE AND FUNCTION OF MACROMOLECULES Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Section A: Polymer principles 1. Most macromolecules are polymers 2. An immense variety of polymers can be built from a small set of monomers Cells join smaller organic molecules together to form larger molecules. These larger molecules, macromolecules, may be composed of thousands of atoms and weigh over 100,000 daltons. The four major classes of macromolecules are: carbohydrates, lipids, proteins, and nucleic acids. Introduction Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Three of the four classes of macromolecules form chainlike molecules called polymers. Polymers consist of many similar or identical building blocks linked by covalent bonds. The repeated units are small molecules called monomers. Some monomers have other functions of their own. 1. Most macromolecules are polymers Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings The chemical mechanisms that cells use to make and break polymers are similar for all classes of macromolecules. Monomers are connected by covalent bonds via a condensation reaction or dehydration reaction. One monomer provides a hydroxyl group and the other provides a hydrogen and together these form water. This process requires energy and is aided by enzymes. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Fig. 5.2a The covalent bonds connecting monomers in a polymer are disassembled by hydrolysis. In hydrolysis as the covalent bond is broken a hydrogen atom and hydroxyl group from a split water molecule attaches where the covalent bond used to be. Hydrolysis reactions dominate the digestive process, guided by specific enzymes. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Fig. 5.2b Each cell has thousands of different macromolecules. These molecules vary among cells of the same individual; . | CHAPTER 5 THE STRUCTURE AND FUNCTION OF MACROMOLECULES Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Section A: Polymer principles 1. Most macromolecules are polymers 2. An immense variety of polymers can be built from a small set of monomers Cells join smaller organic molecules together to form larger molecules. These larger molecules, macromolecules, may be composed of thousands of atoms and weigh over 100,000 daltons. The four major classes of macromolecules are: carbohydrates, lipids, proteins, and nucleic acids. Introduction Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Three of the four classes of macromolecules form chainlike molecules called polymers. Polymers consist of many similar or identical building blocks linked by covalent bonds. The repeated units are small molecules called monomers. Some monomers have other functions of their own. 1. Most macromolecules are polymers Copyright © 2002 Pearson Education, Inc., .