cell biology

cell biology, branch of science that studies the structure, function, and behavior of cells—the fundamental units of living organisms. Cell biology explores the organization of cells, the essential processes they perform, and their role in the formation of tissues. The field connects closely with genetics, biochemistry, and molecular biology and serves a critical role in helping uncover fundamental principles that explain how living systems develop and function.

Aims and approaches

Within cells are specialized structures known as organelles, common examples of which include the nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, ribosomes, and lysosomes. These structures serve essential roles in processes ranging from gene expression and protein synthesis to metabolism, cell signaling, and cell division. Understanding the ways in which organelles and such processes come together to enable cells to maintain homeostasis, communicate through signaling pathways, and adapt to internal and external stimuli is a significant area of investigation in cell biology.

Modern cell biology integrates various techniques and analyses to elucidate details about cell structure and function and cellular dynamics in both health and disease states. Examples include visualization and analysis with microscopy and flow cytometry and the use of assays to measure cytotoxicity and cell viability. Manipulation using techniques such as cell culture and cell fractionation (the separation of cell components) is commonly employed, as are molecular and genetic approaches, particularly polymerase chain reaction (PCR), which is used to amplify DNA for further analysis, and gel electrophoresis, which is used to separate molecules of DNA, RNA, or proteins according to size or electric charge. Insights from investigations employing such techniques and approaches form the foundation for understanding a broad expanse of relevant areas, including biological development, immunology, neurobiology, and cancer biology.

Discover how ordinary objects work, and expand your understanding of the familiar.

SIGN UP

" height="20" alt="HEW Logo">

Thank you for signing up!"

Back to homepage

By clicking "Sign Up", you consent to the Britannica Privacy Policy and Terms of Use.

Britannica Quiz

Biology Bonanza

Historical developments

The earliest phase of cell biology began with English scientist Robert Hooke, who used his compound microscope to carry out investigations of cork in 1665. Hooke observed dead pockets within cork tissue, which were in a pattern resembling a honeycomb and were spotted with little compartments; he introduced the term cell to describe these areas of cork tissue. In the 19th century German botanist Matthias Schleiden (in 1838) and German biologist Theodor Schwann (in 1839) were among the first to clearly state that cells are the fundamental particles of both plants and animals. This pronouncement—which contributed to the development of cell theory—was amply confirmed and elaborated by a series of discoveries and interpretations.

In 1892 German embryologist and anatomist Oscar Hertwig suggested that organismic processes are reflections of cellular processes; he thus established cell biology as a separate branch of biology. Research into the activities of chromosomes led to the founding of cytogenetics, in 1902–04, when American geneticist Walter Sutton and German zoologist Theodor Boveri demonstrated the connection between cell division and heredity.

Since the early 1900s, advances in cell biology have been fueled by developments such as the electron microscope, the discovery of the double-helix backbone of DNA, and the fluid mosaic model, which describes the dynamic nature of the phospholipid bilayer that makes up a cell membrane. Subsequent developments in genetic engineering, fluorescence imaging, and stem cell research deepened insights into cell growth, communication, and disease. Today techniques such as CRISPR gene editing and advances in systems biology, which explores the interactions and behavior of the components of living things, including molecules and cells, have allowed scientists to study and manipulate cells with unprecedented precision.