Basic Concepts In Biochemistry: A Students Survival Guide

BASIC CONCEPTS IN BIOCHEMISTRY A STUDENT'S SURVIVAL GUIDE Second Edition HIRAM F. GILBERT, Ph.D. Professor of Biochemistry Baylor College of Medicine Houston, Texas McGraw-Hill Health Professions Division New York St. Louis San Francisco Auckland Bogotá Caracas Lisbon London Madrid Mexico City Milan Montreal New Delhi San Juan Singapore Sydney Tokyo Toronto • • • • • • • • • • • • BASIC CONCEPTS IN BIOCHEMISTRY, 2/E Copyright © 2000, 1992 by the McGraw-Hill Companies, Inc. All rights reserved. Printed 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 data base or retrieval system, without the prior written permission of the publisher. 1234567890 DOCDOC 99 ISBN 0-07-135657-6 This book was set in Times Roman by Better Graphics, Inc. The editors were Steve Zollo and Barbara Holton; the production supervisor was Richard Ruzycka; the index was prepared by Jerry Ralya. R. R. Donnelley and Sons was the printer and binder. This book is printed on acid-free paper. Cataloging-in-Publication Data is on file for this book at the Library of Congress. • P R O L O G U E • Basic Concepts in Biochemistry: A Student’s Survival Guide is not a conventional book: It is not a review book or a textbook or a problem book. It is a book that offers help in two different ways—help in understanding the concepts of biochemistry and help in organizing your attack on the subject and minimizing the subject’s attack on you. This book presents what are often viewed as the more difficult concepts in an introductory biochemistry course and describes them in enough detail and in simple enough language to make them understandable. We surveyed first- and second-year medical students at a national student meeting asking them to list, in order, the parts of biochemistry they found most difficult to understand. The winner (or loser), by far, was integration of metabolism. Metabolic control, pH, and enzyme kinetics ran closely behind, with notable mention given to molecular biology and proteins. Biochemistry texts and biochemistry professors are burdened with the task of presenting facts, and the enormity of this task can get in the way of explaining concepts. Since I don’t feel burdened by that necessity, I’ve only outlined most of the facts and concentrated on concepts. My rationale is that concepts are considerably easier to remember than facts and that concepts, if appropriately mastered, can minimize the amount of material that has to be memorized—you can just figure everything out when required. In Basic Concepts in Biochemistry, central concepts are developed in a stepwise fashion. The simplest concepts provide a review of what might have been forgotten, and the more complex concepts present what might not have been realized. • • • • • • • xv • • • • • • C O N T E N T Prefa