This book contains 6 sections. The first section covers the chemical basis of life, where molecules found in the human body are introduced to the students. The second section deals with the general metabolism. The third section is clinical and applied biochemistry, where the emphasis is given to clinical applications and the relevance of the study of biochemistry for understanding medical problems. The fourth section is nutrition, and the fifth section describes molecular biology including molecular diagnosis. The final section contains laboratory medicine, HIV, COVID, cancer and other advanced topics.