Final answer:
The four categories of large organic molecules in cells are carbohydrates, lipids, proteins, and nucleic acids, each playing a variety of critical roles.
Step-by-step explanation:
The four different categories of large organic molecules found within cells are carbohydrates, lipids, proteins, and nucleic acids. These biological macromolecules are essential for life and are constructed from smaller organic molecules. Each class of these macromolecules is a vital component of the cell and is involved in a broad range of functions. For instance, proteins act as enzymes and structural elements, carbohydrates provide energy and structural support, lipids serve as the cell's storage form of energy and make up cell membranes, and nucleic acids, such as DNA and RNA, are responsible for the storage and expression of genetic information.