The fundamental unit of biosynthesis in living organisms is the cell. Cells are the basic structural and functional units of life, responsible for all metabolic activities and processes. They engage in biosynthesis by utilizing raw materials to create essential biomolecules, such as proteins, nucleic acids, lipids, and carbohydrates, necessary for growth and maintenance. The study of cellular biology provides insights into how cells interact, communicate, and respond to changes in their environment, highlighting their central role in sustaining life on Earth.