The Irregular Network of Unit Membranes Visible Only by Electron Microscopy That Occurs in the Cytoplasm of Many Eukaryotic Cells. the Membranes Form a Complex Meshwork of Tubular Channels Which Are Often Expanded Into Slitlike Cavities Called Cisternae. the Er Takes Two Forms Rough (or Granular) with Ribosomes Adhering to the Outer Surface and Smooth (with No Ribosomes Attached).
Organized Structure of Distinctive Morphology and Function Bounded by a Single or Double Lipid Bilayer Membrane and Occurring Within the Cell. Includes the Nucleus Mitochondria Plastids Vacuoles and Vesicles. Excludes the Plasma Membrane.
Catalysis of an Oxidation Reduction (redox) Reaction a Reversible Chemical Reaction in Which the Oxidation State of an Atom or Atoms Within a Molecule Is Altered. One Substrate Acts As a Hydrogen or Electron Donor and Becomes Oxidized While the Other Acts As Hydrogen or Electron Acceptor and Becomes Reduced.