The Foundations of Chemistry

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OUTLINE

Shapes of Organic Molecules

28-1 Constitutional Isomers

28-2 Stereoisomers

28-3 Conformations

Selected Reactions

28-4 Reactions of Brønsted–Lowry

Acids and Bases

28-5 Oxidation–Reduction Reactions

28-6 Formation of Carboxylic

Acid Derivatives

28-7 Hydrolysis of Esters

Biopolymers

28-8 Carbohydrates

28-9 Polypeptides and Proteins

28-10 Nucleic Acids

OBJECTIVES

After you have studied this chapter, you should be able to

• Describe the differences between constitutional isomers and stereoisomers


• Distinguish between isomers and conformations


• Describe some common organic acids and bases and their relative strengths


• Recall some reactions that involve oxidation and reduction of organic compounds


• Recall reactions that form carboxylic acid derivatives


• Recall reactions in which esters and amides are formed


• Write equations in which carbonyl groups are used to produce other functional groups


• Write equations showing the hydrolysis of esters (saponification)


• Describe the structure of carbohydrates


• Describe the structure of proteins


• Describe the structure of nucleic acids

SHAPES OF ORGANIC MOLECULES

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s we learned in Chapters 25 and 27, the chemical and physical properties of a

substance depend on the arrangements, as well as the identities, of its atoms.

Isomersare substances that have the same number and kind of atoms—that is, the

same molecular formula—but with different structural formulas. Because their struc-

tures are different, isomers are different substances and have different properties.

Capsaicin, the substance responsible

for the “hot” in peppers, has phenol,

ester, and amide functional groups.

In addition to acting as an

inflammatory agent, it can act as a

pain reliever, presumably by

blocking nerve endings involved in

the transmission of pain.