BIOL 1201 : REVIEW PART 2
Document Summary
Prokaryotic and eukaryotic cells differ in size and complexity. All cells are bounded by a plasma membrane. Bacteria and archaea have prokaryotic cells, without nuclei or other membrane-enclosed organelles. All other organisms have eukaryotic cells, with membrane-enclosed nuclei and other membranous organelles in their cytoplasm. Internal membranes compartmentalize the functions of a eukaryotic cell. Plant and animal cells have most of the same organelles. The nucleus contains a eukaryotic cell"s genetic library. Dna is organized with proteins into thin fibers of chromatin, which coil to form thick chromosomes in dividing cells. Nondividing cells have one or more nucleoli, sites of ribosome synthesis. Macromolecules and ribosomal subunits pass between nucleus and cytoplasm through pores in the nuclear envelope. Many of the eukaryotic cell"s membranes are connected either by physical continuity or through transport vesicles made of pinched-off pieces of membrane. The endoplasmic reticulum manufactures membranes and performs many other biosynthetic functions.
