Preface - Harper’s Illustrated Biochemistry, 29th Edition (2012)

Harper’s Illustrated Biochemistry, 29th Edition (2012)

Preface

The authors and publishers are pleased to present the twenty-ninth edition of Harper’s Illustrated Biochemistry. The first edition of this text, entitled Harper’s Biochemistry, was published in 1939 under the sole authorship of Dr Harold Harper, University of California, San Francisco. Subsequently, various authors have contributed to the text.

Cover Illustration for the Twenty-Ninth Edition

The cover illustration for the 29th edition commemorates Elizabeth H. Blackburn, Carol W. Greider, and Jack W. Szostak, who shared the 2009 Nobel Prize in Physiology or Medicine for their seminal work on telomeres and the enzyme telomerase. Telomeres comprise up to 200 copies of a repeating DNA sequence called a G-quadruplex, a structure named for the unique cyclic arrangement of four sets of four guanine bases hydrogen-bonded in head-to-tail fashion that stabilize this structure. In the illustration, the phosphodiester backbone of the DNA is represented by a ribbon and the guanine bases by filled hexagons fused to filled pentagons. The spectral color gradation from purple to red facilitates tracing the progression of the polynucleotide chain. The four sets of cyclic tetra-guanine units can be seen in center stacked from top to bottom and tilted roughly 45° from left to right (Adapted from Protein Data Bank ID no. 2KKA).

As a consequence of the unidirectional nature of DNA replication, each time a chromosome is replicated, the number of G-quadruplex units is reduced. When the supply of telomere units is completely exhausted, replication ceases and the cell transitions to a senescent state. Scientists speculate that the telomere serves as a countdown clock that limits the number of times a somatic cell can divide, and hence its lifespan.

Changes in the Twenty-Ninth Edition

Consistent with our goal of providing students with a text that describes and illustrates biochemistry in a medically relevant, up-to-date, comprehensive, and yet relatively concise manner, in addition to updating every chapter, significant new material appears in this edition.

Each chapter now begins with a brief statement of its objectives followed by a brief account of its biomedical importance. A major addition is the inclusion of over 250 multiplechoice exam questions with answers given in an answer bank.

Major Additional Changes Include Three Entirely New Chapters:

“Biochemistry of Aging”

“Biochemistry of Cancer”

“Clinical Chemistry”

Additional Significant Changes Include:

• Inclusion of aspects of epidemiology in the chapter on “Bioinformatics and Computational Biology”.

• New figures that illustrate key approaches for identifying possible active sites, ligand-binding sites, and other interaction sites (Section I), and various aspects of metabolism (Section II).

• New tables that summarize aspects of metabolic diseases, including those of purine, pyrimidine, and amino acid metabolism (Section III).

• Expanded discussion of non-coding RNAs, DNA damage repair and human diseases, epigenetic factors that control eukaryotic gene expression, the activities of miRNAs, and powerful new assays to monitor and characterize transcription genome-wide (Section IV).

• New tables that address vitamin and mineral requirements and a greatly expanded discussion of iron metabolism in health and disease (Section VI).

Organization of the Book

Following two introductory chapters, the text is divided into six main sections. All sections and chapters emphasize the medical relevance of biochemistry.

Section I addresses the structures and functions of proteins and enzymes. This section also contains a chapter on Bioinformatics and Computational Biology, reflecting the increasing importance of these topics in modern biochemistry, biology, and medicine.

Section II explains how various cellular reactions either utilize or release energy, and traces the pathways by which carbohydrates and lipids are synthesized and degraded. Also described are the many functions of these molecules.

Section III deals with the amino acids, their metabolic fates, certain features of protein catabolism, and the biochemistry of the porphyrins and bile pigments.

Section IV describes the structure and function of nucleotides and nucleic acids, DNA replication and repair, RNA synthesis and modification, protein synthesis, the principles of recombinant DNA technology, and new understanding of how gene expression is regulated.

Section V deals with aspects of extracellular and intracellular communication. Topics include membrane structure and function, the molecular bases of the actions of hormones, and the field of signal transduction.

Section VI includes fifteen special topics: nutrition, digestion, and absorption; vitamins and minerals; free radicals and antioxidants; intracellular trafficking and sorting of proteins; glycoproteins; the extracellular matrix; muscle and the cytoskeleton; plasma proteins and immunoglobulins; hemostasis and thrombosis; red and white blood cells; the metabolism of xenobiotics; the biochemistry of aging; the biochemistry of cancer; clinical chemistry; and sixteen biochemically oriented case histories. The latter chapter concludes with a brief epilog indicating some major challenges for medicine for which biochemistry and related disciplines will play important roles in finding solutions.

Appendix lists useful web sites and biochemical journals and others with significant biochemical content.