Unit 3:  How Are Eukaryotic Cells Organized into Smaller Parts?

Scientists aren't just interested in the individual molecules found in cells or in cells' metabolic functions and pathways; they also seek to learn more about the ways in which larger groupings of molecules serve cells. These groupings take on many forms and are responsible for a wide variety of functions. For instance, a cell's membranes make up its outer boundary and partition off its organelles, and its cytoskeleton provides three-dimensional support and the means for movement. Other specialized structures, such as mitochondria, chloroplasts, and cell walls, have evolved to carry out vital functions, but they are found only in specific categories of cells. Therefore, understanding these structures not only provides insight into cellular function, but it also helps elucidate the differences between various types of organisms.