Biochemistry is the science of chemical processes in living systems. A living organism is a complex system of organs and tissues that are able to change shape and volume in response to internal and external signals, and to move and respond to external stimuli. A cell is the basic unit of life, the smallest component of a living organism. All cells have the same basic structure, they are composed of a plasma membrane that surrounds a region of cytoplasm, in which reside the organelles necessary for the cell to function.

Molecular biology is the study of the genetic material, the molecules of which are responsible for the development of all living organisms. A living organism is a system that is capable of transmitting and storing information, and of producing new organisms. Information is stored in the genes, which are molecules composed of DNA. The process of information transfer from DNA to RNA is known as transcription.