The application of modern chemistry and physics theories, techniques and methods has promoted the research on the structure and function of biological macromolecules. Molecular biology is closely related to biochemistry and biophysics. The main differences between them are as follows:

(1) Biochemistry and biophysics use chemical and physical methods to study biological problems at different levels, such as molecular level, cell level, whole level and even group level. Molecular biology focuses on studying the universal laws of life activities at the molecular level (including multi-molecular systems);

(2) At the molecular level, molecular biology focuses on macromolecules, mainly protein, nucleic acids, lipid systems and some polysaccharides and their complex systems. The transformation of some small molecular substances in organisms belongs to the category of biochemistry;

(3) The main purpose of molecular biology research is to clarify the basic characteristics shared by the whole biological world at the molecular level, that is, the essence of life phenomena; The study of physical and chemical phenomena or changes of a specific organism or a specific organ in an organism belongs to the category of biophysics or biochemistry.