Lippincott’s Illustrated Q&A Review of Biochemistry

Book Preface

The molecular basis of disease is best understood through a thorough comprehension of biochemistry  and molecular biology. Diseases alter the normal fl ow of metabolites through biochemical pathways, and  treatment of disease is aimed toward restoring this normal fl ow. Why should an inability to metabolize  phenylalanine lead to neuronal damage? Why is an inability to transmit the insulin signal so detrimental  to long-term survival? Why is obesity linked to heart disease and diabetes? Understanding biochemistry  provides insights into understanding the human body, which is the basis of medicine. Understanding  biochemistry allows the student to recognize how a basic pathway has malfunctioned, to think through  the pathophysiology results and treatment possibilities, to rationally differentiate pharmacotherapeutic  treatment, and to understand and predict the unwanted side effects of pharmaceuticals. All of these skills  are critical to the practice of medicine. The questions in this book are geared toward allowing the student  to learn and apply biochemical principles to disease states.

This book has been designed to present questions that take the student through the various aspects  of biochemistry, starting with the basic chemical building blocks of the discipline through human genetics and the biochemistry of cancer. The questions have been written such that students completing their  second year of medical school should be able to answer them, although fi rst year students can also use  the book as they review biochemistry. Many of the questions were written in National Board format and  require two levels of thought. The fi rst is to determine a diagnosis from the information presented in the  question, and the second is to understand the biochemistry behind the diagnosis. However, understanding biochemistry also requires an understanding of the vocabulary of the subject, and many of the online  questions will test a student’s understanding of the vocabulary.

All questions are written such that one best answer is required, and the explanations accompanying  the questions are designed to reinforce the biochemistry underlying the question. As biochemistry is a  cumulative subject, concepts learned in earlier chapters are required to aid in answering questions in later  chapters. Working through the 630 questions associated with the book and online materials will enable  a student to better master the relationship between biochemistry and medicine.

In a book of this nature, it is possible that certain questions will have mixed interpretations (twentyfi ve years of teaching medical students has defi nitely brought that point home to the authors). Any errors  in the book are the sole responsibility of the authors, and they would like to be informed of such errors,  or alternative interpretations, by the readers. Through this feedback, future printings of the book will reflect the correction of these errors.

The authors would like to thank the staff at LWW for their assistance in the preparation of this manuscript, particularly Ms Kelley Squazzo, for her patience with the authors as they struggled, at times, to  write the perfect questions. We would also like to thank the reviewers of the manuscript for their excellent comments for improving the questions found in the text. Finally, the authors would also like to thank  the many classes of medical students whom they have taught for their feedback on the questions we have  used to evaluate them as they progressed through their fi rst year of medical school. This feedback has  proved to be invaluable to the authors as they continually assess and modify their evaluation methods  every year

Contents
Preface and Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
Chapter 1 Biochemical Compounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Chapter 2 Protein Structure and Function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Chapter 3 DNA Structure, Replication, and Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Chapter 4 RNA Synthesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Chapter 5 Protein Synthesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Chapter 6 Regulation of Gene Expression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Chapter 7 Molecular Medicine and Techniques. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Chapter 8 Energy Metabolism Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Chapter 9 Hormones and Signaling Mechanisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Chapter 10 Glycolysis and Gluconeogenesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Chapter 11 TCA Cycle and Oxidative Phosphorylation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Chapter 12 Glycogen Metabolism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Chapter 13 Fatty Acid Metabolism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Chapter 14 HMP Shunt and Oxidative Reactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Chapter 15 Amino Acid Metabolism and the Urea Cycle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
Chapter 16 Phospholipid Metabolism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Chapter 17 Whole-body Lipid Metabolism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
Chapter 18 Purine and Pyrimidine Metabolism. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
Chapter 19 Diabetes and Metabolic Syndrome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
Chapter 20 Nutrition and Vitamins. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
Chapter 21 Human Genetics and Cancer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
Figure Credits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200