Basic Cell Biology I. Cytoplasm A. Plasma membrane B. Mitochondria C. Ribosomes D. Endoplasmic reticulum 1. Rough 2. Smooth E. Golgi apparatus F. Lysosomes G. Cytoskeleton II. Nucleus A. Nuclear Envelope B. Chromatin C. Nucleolus D. Nuclear matrix III. Cell division © 2002 by Bruce Alberts, Alexander Johnson, Julian Lewis, Martin Raff, Keith Roberts, and Peter Walter. Asymmetrical arrangement of phospholipids in plasma membrane ATP-dependent phospholipid translocase Molecular Cell Biology, Lodish et al., 4 th edition. Figure 2—1. The ultrastructure and molecular organization (right) of the cell membrane. The dark lines at left represent the two dense layers observed in the electron microscope; these are caused by the deposit of osmium in the hydrophilic portions of the phospholipid molecules. [...]... the secondary lysosome creates a residual body, containing remnants of undigested molecules In some cells, such as osteoclasts, the lysosomal enzymes are secreted to the extracellular environment Nu, nucleolus Cytoskeleton Microtubules Microfilaments Intermediate filaments Function Maintain cell shape Cell movement (diapedesis) Cytoplasm movement (ie transport of secretory granules) ... Walter Figure 2—19 The ultrastructure of a cell that synthesizes (but does not secrete) proteins on free polyribosomes (A); a cell that synthesizes, segregates, and stores proteins in organelles (B); a cell that synthesizes, segregates, and directly exports proteins (C); and a cell that synthesizes, segregates, stores in supranuclear granules, and exports proteins (D) SER Structure Lacks polyribosomes,... proteolysis Packing and concentration of secretory granules Apical Basal Lysosomes Membrane bound vesicles that contain hydrolytic enzymes for digestion Heterophagy Digestion of extracellular material Autophagy digestion of intracellular organelles Review Table 2-3 for clinical correlations Eg Tay-Sachs disease- accumulation of glycolipid in nerves Figure 2—27 Current concepts of the functions of lysosomes... basophilic Prominent in protein synthesizing cells Functions Synthesize proteins with the following destinations: Storage in lysosomes Storage in secretory granules Use as integral proteins SRP- 6 non-identical proteins, 7 S RNA © 2002 by Bruce Alberts, Alexander Johnson, Julian Lewis, Martin Raff, Keith Roberts, and Peter Walter Figure 2—19 The ultrastructure of a cell that synthesizes (but does not secrete)...Figure 11—14 Electron micrograph of a transverse section of a continuous capillary Note the nucleus (N) and the junctions between neighboring cells (arrowheads) Numerous pinocytotic vesicles are evident (small arrows) C Ribosomes Structure- 2 subunits, composed of 4 types of RNA and 80 different proteins RNA is synthesized in the nucleolus . Basic Cell Biology I. Cytoplasm A. Plasma membrane B. Mitochondria C. Ribosomes D translocase Molecular Cell Biology, Lodish et al., 4 th edition. Figure 2—1. The ultrastructure and molecular organization (right) of the cell membrane. The