Preface to the Sixth Edition 

We are glad to present the sixth edition of the Textbook of Biochemistry for Medical Students. With this sixth edition, 
the textbook is entering the 1 6th year of existence. With humility, we may state that the medical community of India 
has warmly received the previous editions of this book. Many medical colleges and universities in India have accepted 
it as one of the standard textbooks. We are happy to note that this book has also reached in the hands of medical 
students of neighboring countries of Nepal, Pakistan, Bangladesh, Sri Lanka, etc. and also to distant countries in 
Africa and Europe. Apart from the medical community, this book has also become popular to other biology group of 
students in India. In retrospect, it gives immense satisfaction to note that this book served the students and faculty for 
the past one and half decades. 

At this time, a revision of the textbook has become absolutely necessary for two reasons. Firstly, the Medical 
Council of India has revised the syllabus for biochemistry, especially enhancing the topics on Clinical Biochemistry. 
Accordingly, we have made elaborate changes in the order of chapters, old chapters on clinical chemistry have been 
extensively updated and clinically relevant points were further added. Secondly, rapid progress has been made in the 
area of molecular biology during past few years, and these advances are to be reflected in this book also. The major 
change in this sixth edition is that advanced knowledge has been added in almost all pages, a few sentences were 
added here and there in almost all pages; sometimes, a few pages are newly incorporated; while it became necessary 
to include a few new chapters also. 

From the first edition onwards, our policy was to provide not only basic essentials but also some of the advanced 
knowledge. About 30% contents of the previous editions were not required for a student aiming for a minimum pass. 
A lot of students have appreciated this approach, as it helped them to pass the PG entrance examinations at a later 
stage. However, this asset has paved the way for a general criticism that the extra details are a burden to the average 
students. Especially when read for the first time, the student may find it difficult to sort out the essential minimum from 
the desirable bulk. So, in the fifth edition, we have promised that we shall make two different books, one for MBBS and 
another one for postgraduate courses in Biochemistry. Thus, the content has been reduced substantially in the last 
edition. But, due to various reasons, most of which beyond the control of the authors, the postgraduate book could not 
be published. This led to the criticism that the content is sub-optimal. Many PG students were enquiring about the 
advanced book. The advanced students felt that they were neglected. This 6th edition is a compromise. Advanced 
topics are given in small prints. In essence, this book has three components; rather this book is composed of three 
books. The bold printed areas will be useful for the students at the time of revision just before the examinations; regular 
printed pages are meant for an average first year MBBS student (must-know areas) and the fine printed paragraphs are 
targeted to the advanced students preparing for the PG entrance (desirable to know areas). The readability has been 
markedly improved by increasing the font size in the regular areas. 

Essay and short notes questions, problem solving exercises, viva voce, quick look, multiple choice questions 
(MCQs) are given as a separate book, but free of cost. These questions are compiled from the question papers of 
various universities during the last decade. These questions will be ideal for students for last-minute preparation for 

A textbook will mature only by successive revisions. In the preface for the first edition, we expressed our desire to 
revise the textbook every 3 years. We were fortunate to keep that promise. This book has undergone metamorphosis 
during each edition. Chemical structures with computer technology were introduced in the second edition. Color 
printing has been launched in the third edition. The fourth edition came out with multicolor printing. In the fifth edition, 
the facts were presented in small paragraphs and that too with numbers, so as to aid memorization. In this sixth 
edition, figures are drastically increased; there are now about 1 ,1 00 figures, 230 tables and 200 boxes (perhaps we 
could call it as Illustrated Textbook of Biochemistry), altogether making the book more student-friendly. The quality of 
paper is also improved during successive editions. 

We were pleasantly surprised to receive many letters giving constructive criticisms and positive suggestions to 
improve the textbook. These responses were from all parts of the country (we got a few such letters from African 
students also). Such contributors include Heads of Departments, very senior professors, middle level teachers and 
mostly postgraduate students. We have tried to incorporate most of those suggestions, within the constraints of page