tailieunhanh - Lecture Organic chemistry: Chapter 24 - L. G. Wade, Jr.

This chapter introduce to amino acids, peptides, and proteins. In this chapter, students will be able to: Name amino acids and peptides, and draw the structures from their names. Explain why the naturally occurring amino acids are called L-amino acids; identify which amino acids are acidic, which are basic, and which are neutral; show how to synthesize amino acids from simpler compounds, and show how to combine amino acids in the proper sequence to synthesize a peptide. | Chapter 24 Copyright © 2010 Pearson Education, Inc. Organic Chemistry, 7th Edition L. G. Wade, Jr. Amino Acids, Peptides, and Proteins Chapter 24 Proteins Biopolymers of -amino acids. Amino acids are joined by peptide bond. They serve a variety of functions: Structure Enzymes Transport Protection Hormones Chapter 24 Structure of Proteins Chapter 24 Amino Acids —NH2 on the carbon next to —COOH. Glycine, NH2—CH2—COOH, is simplest. With —R side chain, molecule is chiral. Most natural amino acids are L-amino acids, related to L-(-)-glyceraldehyde. Direction of optical rotation, (+) or (-), must be determined experimentally. Chapter 24 Stereochemistry of -Amino Acids Chapter 24 Standard Amino Acids Twenty standard -amino acids. Differ in side-chain characteristics: —H or alkyl Contains an —OH Contains sulfur Contains a nonbasic nitrogen Has —COOH Has a basic nitrogen Chapter 24 Essential Amino Acids Arginine (Arg) Threonine (Thr) Lysine . | Chapter 24 Copyright © 2010 Pearson Education, Inc. Organic Chemistry, 7th Edition L. G. Wade, Jr. Amino Acids, Peptides, and Proteins Chapter 24 Proteins Biopolymers of -amino acids. Amino acids are joined by peptide bond. They serve a variety of functions: Structure Enzymes Transport Protection Hormones Chapter 24 Structure of Proteins Chapter 24 Amino Acids —NH2 on the carbon next to —COOH. Glycine, NH2—CH2—COOH, is simplest. With —R side chain, molecule is chiral. Most natural amino acids are L-amino acids, related to L-(-)-glyceraldehyde. Direction of optical rotation, (+) or (-), must be determined experimentally. Chapter 24 Stereochemistry of -Amino Acids Chapter 24 Standard Amino Acids Twenty standard -amino acids. Differ in side-chain characteristics: —H or alkyl Contains an —OH Contains sulfur Contains a nonbasic nitrogen Has —COOH Has a basic nitrogen Chapter 24 Essential Amino Acids Arginine (Arg) Threonine (Thr) Lysine (Lys) Valine (Val) Phenylalanine (Phe) Tryptophan (Trp) Methionine (Met) Histidine (His) Leucine (Leu) Isoleucine (Ile) Chapter 24 Figure: Title: Standard Amino Acids Caption: There are 20 alpha-amino acids, called the standard amino acids, that are found in nearly all proteins. Notes: The standard amino acids differ from each other in the structure of the side chains bonded to their α carbon atoms. Chapter 24 Figure: Title: Standard Amino Acids Caption: There are 20 alpha-amino acids, called the standard amino acids, that are found in nearly all proteins. Notes: The standard amino acids differ from each other in the structure of the side chains bonded to their α carbon atoms. Chapter 24 Chapter 24 Complete Proteins Provide all the essential amino acids. Examples: Those found in meat, fish, milk, and eggs. Plant proteins are generally incomplete. Vegetarians should eat many different kinds of plants, or supplement their .