Biochemistry

237 Pages·2007·2.768 MB·English

by  Richard G MacDonald, William G Chaney

LANGE
N
USMLE
ROAD MAP
BIOCHEMISTRY
This page intentionally left blank
LANGE
N
USMLE
ROAD MAP
BIOCHEMISTRY
RICHARD G. MACDONALD
Department of Biochemistry and Molecular Biology
University of Nebraska Medical Center
Omaha, Nebraska
WILLIAM G. CHANEY
Department of Biochemistry and Molecular Biology
University of Nebraska Medical Center
Omaha, Nebraska
New York Chicago San Francisco Lisbon London Madrid Mexico City
Milan New Delhi San Juan Seoul Singapore Sydney Toronto
Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved. Manufactured in the United States of America. Except as
permitted under the United States Copyright Act of 1976, no part of this publication may be reproduced or distributed in any form or by
any means, or stored in a database or retrieval system, without the prior written permission of the publisher.
0-07-159319-5
The material in this eBook also appears in the print version of this title: 0-07-144205-7.
All trademarks are trademarks of their respective owners. Rather than put a trademark symbol after every occurrence of a trademarked
name, we use names in an editorial fashion only, and to the benefit of the trademark owner, with no intention of infringement of the
trademark. Where such designations appear in this book, they have been printed with initial caps.
McGraw-Hill eBooks are available at special quantity discounts to use as premiums and sales promotions, or for use in corporate training
programs. For more information, please contact George Hoare, Special Sales, at [email protected] or [phone].
TERMS OF USE
This is a copyrighted work and The McGraw-Hill Companies, Inc. (“McGraw-Hill”) and its licensors reserve all rights in and to the work.
Use of this work is subject to these terms. Except as permitted under the Copyright Act of 1976 and the right to store and retrieve one copy
of the work, you may not decompile, disassemble, reverse engineer, reproduce, modify, create derivative works based upon, transmit, dis-
tribute, disseminate, sell, publish or sublicense the work or any part of it without McGraw-Hill’s prior consent. You may use the work for
your own noncommercial and personal use; any other use of the work is strictly prohibited. Your right to use the work may be terminated
if you fail to comply with these terms.
THE WORK IS PROVIDED “AS IS.” McGRAW-HILL AND ITS LICENSORS MAKE NO GUARANTEES OR WARRANTIES AS TO
THE ACCURACY, ADEQUACY OR COMPLETENESS OF OR RESULTS TO BE OBTAINED FROM USING THE WORK,
INCLUDING ANY INFORMATION THAT CAN BE ACCESSED THROUGH THE WORK VIA HYPERLINK OR OTHERWISE, AND
EXPRESSLY DISCLAIM ANY WARRANTY, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. McGraw-Hill and its licensors do not
warrant or guarantee that the functions contained in the work will meet your requirements or that its operation will be uninterrupted or
error free. Neither McGraw-Hill nor its licensors shall be liable to you or anyone else for any inaccuracy, error or omission, regardless of
cause, in the work or for any damages resulting therefrom. McGraw-Hill has no responsibility for the content of any information accessed
through the work. Under no circumstances shall McGraw-Hill and/or its licensors be liable for any indirect, incidental, special, punitive,
consequential or similar damages that result from the use of or inability to use the work, even if any of them has been advised of the
possibility of such damages. This limitation of liability shall apply to any claim or cause whatsoever whether such claim or cause arises in
contract, tort or otherwise.
DOI: 10.1036/0071442057
Professional
Want to learn more?
We hope you enjoy this
McGraw-Hill eBook! If
you’d like more information about this book,
its author, or related books and websites,
please click here.
For more information about this title, click here
C O N T E N T S
Abbreviations x
Acknowledgments xi
1 Physiologic Chemistry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
I. Water 1
II. Electrolytes 1
III. Acids and Bases 2
IV. pH 2
V. Buffers 3
VI. Amphipathic Molecules 6
Clinical Problems 6
Answers 8
2 Protein Structure and Function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
I. Amino Acids 9
II.Charge Characteristics of Amino Acids and Proteins 10
III. Protein Structure 11
IV. Collagen 13
V. The Oxygen Binding Proteins—-Myoglobin and Hemoglobin 15
VI. Antibodies 19
Clinical Problems 19
Answers 21
3 The Physiologic Roles of Enzymes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
I. Enzyme-Catalyzed Reactions 23
II. Enzyme Classification 25
III. Catalysis of Reactions by Enzymes at Physiologic Temperature 26
IV. Mechanisms of Enzyme Catalysis 27
V. Kinetics of Enzyme-Catalyzed Reactions 29
VI. Enzyme Inhibitors 30
VII. Coenzymes and Cofactors 32
VIII. Allosteric Regulation of Enzymes 33
Clinical Problems 34
Answers 36
4 Cell Membranes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
I. Overview of Membrane Structure and Function 37
II. Membrane Components: Lipids 37
III. Organization of the Lipid Bilayer 39
IV. Membrane Components: Proteins 42
V. Membrane Components: Carbohydrates 42
VI. Transmembrane Transport 44
Clinical Problems 48
Answers 50
v
N
vi Contents
5 Metabolic Interrelationships and Regulation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
I. Diet and Nutritional Needs 52
II. Regulation of Metabolic Pathways 54
III. Glucose Homeostasis 56
IV. Metabolism in the Fed State 58
V. Metabolism in the Fasting State 61
VI. Metabolism During Starvation 63
Clinical Problems 66
Answers 68
6 Carbohydrate Metabolism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
I. Digestion and Absorption of Dietary Carbohydrates 70
II. Glycolysis 70
III. Regeneration of NAD+ 73
IV. Pentose Phosphate Pathway 76
V. Key Enzymes Regulating Rate-Limiting Steps of Glucose Metabolism 78
VI. Glycogen Metabolism 78
VII. Gluconeogenesis 82
VIII. Metabolism of Galactose and Fructose 85
Clinical Problems 87
Answers 88
7 The TCA Cycle and Oxidative Phosphorylation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
I. Overview of the Tricarboxylic Acid (TCA) Cycle 90
II. Biosynthesis of Acetyl CoA 90
III. Steps of the TCA Cycle 92
IV. Regulation of the TCA Cycle 94
V. Role of the TCA Cycle in Metabolic Reactions 94
VI. Synthesis of Oxaloacetate from Pyruvate 95
VII. The Electron Transport Chain 96
VIII. Energy Capture During Electron Transport 97
IX. Energy Yield of Oxidative Phosphorylation 97
X. Inhibitors of ATP Generation 97
Clinical Problems 99
Answers 101
8 Lipid Metabolism. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
I. Digestion and Absorption of Dietary Fats 103
II. The Lipoproteins: Processing and Transport of Fats 104
III. Functions of Fatty Acids in Physiology 105
IV. Fatty Acid Synthesis 106
V. Fatty Acid Oxidation 109
VI. Metabolism of Ketone Bodies 113
VII. Cholesterol Metabolism 115
VIII. Uptake of Particles and Large Molecules by the Cell 117
Clinical Problems 118
Answers 120
9 Nitrogen Metabolism. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
I. Digestion of Dietary Proteins 122
II. Metabolism of Ammonia 123
III. The Urea Cycle 124
IV. Catabolism of Amino Acids 126
N
Contents vii
V. Biosynthesis of Amino Acids 129
VI. Porphyrin Metabolism 131
Clinical Problems 135
Answers 137
10 Nucleic Acid Metabolism. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
I. Structures and Functions of Nucleotides 139
II. Biosynthesis of Purines 139
III. Biosynthesis of Pyrimidines 142
IV. Degradation of Purine and Pyrimidine Nucleotides 146
V. Salvage Pathways 147
Clinical Problems 148
Answers 149
11 Nucleic Acid Structure and Function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
I. Overview of Nucleic Acid Function 151
II. Structure of Chromosomal DNA 152
III. Replication 154
IV. Mutations and DNA Repair 158
V. RNA Structure 160
VI. Transcription 161
Clinical Problems 164
Answers 166
12 Gene Expression. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
I. The Genetic Code 168
II. Steps in Translation 168
III. Post-translational Modification of Proteins 173
IV. Regulation of Gene Expression 176
V. Mutations 179
Clinical Problems 181
Answers 183
13 Human Genetics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
I. Overview of Mendelian Inheritance 185
II. Modes of Inheritance in Single-Gene Disorders 186
III. Major Concepts in Human Genetics 192
IV. Population Genetics: The Hardy-Weinberg Law 194
Clinical Problems 195
Answers 198
14 Cellular Signaling and Cancer Biology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
I. General Principles of Cellular Signaling 200
II. Signaling by G Protein-Coupled Receptors 201
III. Receptor Tyrosine Kinases 206
IV. The Nuclear Receptor Superfamily 207
V. Overview of Cancer Biology 210
VI. Oncogenes and Tumor Suppressor Genes 210
VII. Apoptosis 213
Clinical Problems 215
Answers 217
Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218
This page intentionally left blank