Cell biology is the branch of science dedicated to the study of cells, defining them as the basic structural, functional, and biological unit of all known organisms. This field explores the complex mechanisms operating within cellular boundaries, examining both prokaryotic and eukaryotic organizational structures. Key areas of investigation include membrane dynamics, the function of organelles such as mitochondria and endoplasmic reticulum, and the biochemical processes of metabolism. Studies focus on fundamental processes like energy conversion, genetic replication, signal transduction, and structural maintenance, providing foundational knowledge about life at its most minute scale.