PREFACE
For several generations of students and teachers, Biochemistry has been an invaluable resource, presenting the concepts and details of molecular structure, metabolism, and laboratory techniques in a streamlined and engaging way. Biochemistry’s success in helping students learn the subject for the first time is built on a number of hallmark features:
Clear writing and simple illustrations. The language of biochemistry is made as accessible as possible for students learning the subject for the first time. To complement the straightforward language and organization of concepts in the text, figures illustrate a single concept at a time to help students see main points without the distraction of excess detail.
Physiological relevance. It has always been our goal to help students connect biochemistry to their own lives on a variety of scales. Pathways and processes are presented in a physiological context so students can see how biochemistry works in the body and under different conditions, and Clinical Application sections in every chapter show students how the concepts they are studying impact human health. The eighth edition includes a number of new Clinical Application sections based on recent discoveries in biochemistry and health.
Evolutionary perspective. Discussions of evolution are woven into the narrative of the text, just as evolution shapes every pathway and molecular structure described in the text. Molecular Evolution sections highlight important milestones in the evolution of life as a way to provide context for the processes and molecules being discussed.
Problem-
solving practice. Every chapter of Biochemistry provides numerous opportunities for students to practice problem- solving skills and apply the concepts described in the text. End- of- chapter problems are divided into three categories to address different problem- solving skills: Mechanism problems ask students to suggest or describe a chemical mechanism; Data interpretation problems ask students to draw conclusions from data taken from real research papers; and chapter integration problems require students to connect concepts from across chapters. Further problem- solving practice is provided online, on the Biochemistry LaunchPad. A variety of molecular structures. All molecular structures in the book, with few exceptions, have been selected and rendered by Jeremy Berg and Gregory Gatto to emphasize the aspect of structure most important to the topic at hand. Students are introduced to realistic renderings of molecules through a molecular model “primer” in the appendices to Chapters 1 and 2 so they are well-
equipped to recognize and interpret the structures throughout the book. Figure legends direct students explicitly to the key features of a model, and often include PDB numbers so the reader can access the file used in generating the structure from the Protein Data Bank website (www.pdb.org). Students can explore molecular structures further online through the Living Figures, in which they can rotate 3D models of molecules and view alternative renderings.
vi
In this revision of Biochemistry, we focused on building on the strengths of the previous editions to present biochemistry in an even more clear and streamlined manner, as well as incorporating exciting new advances from the field. Throughout the book, we have updated explanations of basic concepts and bolstered them with examples from new research. Some new topics that we present in the eighth edition include:
Environmental factors that influence human biochemistry (Chapter 1)
Genome editing (Chapter 5)
Horizontal gene transfer events that may explain unexpected branches of the evolutionary tree (Chapter 6)
Penicillin irreversibly inactivating a key enzyme in bacterial cell-
wall synthesis (Chapter 8) Scientists watching single molecules of myosin move (Chapter 9)
Glycosylation functions in nutrient sensing (Chapter 11)
The structure of a SNARE complex (Chapter 12)
The mechanism of ABC transporters (Chapter 13)
The structure of the gap junction (Chapter 13)
The structural basis for activation of the β-adrenergic receptor (Chapter 14)
Excessive fructose consumption can lead to pathological conditions (Chapter 16)
Alterations in the glycolytic pathway by cancer cells (Chapter 16)
Regulation of mitochondrial ATP synthase (Chapter 18)
Control of chloroplast ATP synthase (Chapter 19)
Activation of rubisco by rubisco activase (Chapter 20)
vii
The role of the pentose phosphate pathway in rapid cell growth (Chapter 20)
Biochemical characteristics of muscle fiber types (Chapter 21)
Alteration of fatty acid metabolism in tumor cells (Chapter 22)
Biochemical basis of neurological symptoms of phenylketonuria (Chapter 24)
Ribonucleotide reductase as a chemotherapeutic target (Chapter 25)
The role of excess choline in the development of heart disease (Chapter 26)
Cycling of the LDL receptor is regulated (Chapter 26)
The role of ceramide metabolism in stimulating tumor growth (Chapter 26)
The extraordinary power of DNA repair systems illustrated by Deinococcus radiodurans (Chapter 28)
The structural details of ligand binding by TLRs (Chapter 34)
viii