Cèllules

Cèllules are the basic structural and functional units of all known living organisms. They carry out the processes necessary for life, including energy conversion, growth, and reproduction, and they contain the genetic material that guides cellular activity.

Two major types are prokaryotic and eukaryotic. Prokaryotic cells, found in bacteria and archaea, lack a defined nucleus and most organelles. Eukaryotic cells, which make up plants, animals, fungi, and protists, have a nucleus and numerous membrane-bound organelles.

Common features of many cells include a plasma membrane that encloses the cell, cytoplasm where most metabolism occurs, and ribosomes for protein synthesis. In eukaryotes, the nucleus stores DNA, while mitochondria generate most of the cell’s energy. Plant and algal cells also contain chloroplasts for photosynthesis, as well as a rigid cell wall and a large central vacuole.

Genetic information is organized into DNA, which is replicated during cell division. Cells reproduce by mitosis in somatic tissues, producing two genetically identical daughter cells, or by meiosis in germ lines, producing gametes with half the chromosome number.

Cells form tissues, organs, and organ systems through differentiation and specialization. Stem cells retain the ability to become multiple cell types and are central to development and regenerative medicine.

Historically, the term derives from Latin cellula. The discovery of cells began with Robert Hooke in 1665, followed by improvements in microscopy by Anton van Leeuwenhoek, and the development of the cell theory by Matthias Schleiden, Theodor Schwann, and Rudolf Virchow in the 19th century.

Studied via light and electron microscopy, cèllules remain central to biology and medicine, underpinning fields from pathology to biotechnology.