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Ch03 b,living units.mission

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Ch03 b,living units.mission

  1. 1. Human Anatomy & Physiology SEVENTH EDITION Elaine N. Marieb Katja Hoehn Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings PowerPoint® Lecture Slides prepared by Vince Austin, Bluegrass Technical and Community College C H A P T E R 3 Cells: The Living Units P A R T B
  2. 2. Active Transport  Uses ATP to move solutes across a membrane  Requires carrier proteins Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
  3. 3. Types of Active Transport  Symport system – two substances are moved across a membrane in the same direction  Antiport system – two substances are moved across a membrane in opposite directions Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
  4. 4. Types of Active Transport  Primary active transport – hydrolysis of ATP phosphorylates the transport protein causing conformational change  Secondary active transport – use of an exchange pump (such as the Na+-K+ pump) indirectly to drive the transport of other solutes Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
  5. 5. Types of Active Transport Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.11
  6. 6. Vesicular Transport  Transport of large particles and macromolecules across plasma membranes  Exocytosis – moves substance from the cell interior to the extracellular space  Endocytosis – enables large particles and macromolecules to enter the cell Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
  7. 7. Vesicular Transport  Transcytosis – moving substances into, across, and then out of a cell  Vesicular trafficking – moving substances from one area in the cell to another  Phagocytosis – pseudopods engulf solids and bring them into the cell’s interior Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
  8. 8. Vesicular Transport  Fluid-phase endocytosis – the plasma membrane infolds, bringing extracellular fluid and solutes into the interior of the cell  Receptor-mediated endocytosis – clathrin-coated pits provide the main route for endocytosis and transcytosis  Non-clathrin-coated vesicles – caveolae that are platforms for a variety of signaling molecules Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
  9. 9. Exocytosis Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.12a
  10. 10. Clathrin-Mediated Endocytosis Extracellular Cytoplasm fluid Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.13a Recycling of membrane and receptors (if present) to plasma membrane Extracellular fluid Plasma membrane Detachment of clathrin-coated vesicle Clathrin-coated vesicle Uncoated vesicle Uncoating Uncoated vesicle fusing with endosome Exocytosis of vesicle contents Endosome Transcytosis To lysosome for digestion and release of contents Clathrin-coated pit Plasma membrane Ingested substance Clathrin protein (a) Clathrin-mediated endocytosis 2 1 3
  11. 11. Clathrin-Mediated Endocytosis Clathrin-coated pit Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.13a Extracellular Cytoplasm fluid Extracellular fluid Plasma membrane Plasma membrane Ingested substance (a) Clathrin-mediated endocytosis
  12. 12. Clathrin-Mediated Endocytosis Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.13a Extracellular Cytoplasm fluid Extracellular fluid Plasma membrane Detachment of clathrin-coated vesicle Clathrin-coated vesicle Clathrin-coated pit Plasma membrane Ingested substance (a) Clathrin-mediated endocytosis
  13. 13. Clathrin-Mediated Endocytosis Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.13a Extracellular Cytoplasm fluid Extracellular fluid Plasma membrane Detachment of clathrin-coated vesicle Clathrin-coated vesicle Uncoated vesicle Uncoating Uncoated vesicle fusing with endosome Endosome Clathrin-coated pit Plasma membrane Ingested substance Clathrin protein (a) Clathrin-mediated endocytosis
  14. 14. Clathrin-Mediated Endocytosis Extracellular Cytoplasm fluid 1 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.13a Recycling of membrane and receptors (if present) to plasma membrane Extracellular fluid Plasma membrane Detachment of clathrin-coated vesicle Clathrin-coated vesicle Uncoated vesicle Uncoating Uncoated vesicle fusing with endosome Endosome Clathrin-coated pit Plasma membrane Ingested substance Clathrin protein (a) Clathrin-mediated endocytosis
  15. 15. Clathrin-Mediated Endocytosis Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.13a Extracellular Cytoplasm fluid Extracellular fluid Plasma membrane Detachment of clathrin-coated vesicle Clathrin-coated vesicle Uncoated vesicle Uncoating Uncoated vesicle fusing with endosome Endosome To lysosome for digestion and release of contents Clathrin-coated pit Plasma membrane Ingested substance Clathrin protein (a) Clathrin-mediated endocytosis 2
  16. 16. Clathrin-Mediated Endocytosis Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.13a Extracellular Cytoplasm fluid Extracellular fluid Plasma membrane Detachment of clathrin-coated vesicle Clathrin-coated vesicle Uncoated vesicle Uncoating Uncoated vesicle fusing with endosome Exocytosis of vesicle contents Endosome Transcytosis Clathrin-coated pit Plasma membrane Ingested substance Clathrin protein (a) Clathrin-mediated endocytosis 3
  17. 17. Clathrin-Mediated Endocytosis Extracellular Cytoplasm fluid Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.13a Recycling of membrane and receptors (if present) to plasma membrane Extracellular fluid Plasma membrane Detachment of clathrin-coated vesicle Clathrin-coated vesicle Uncoated vesicle Uncoating Uncoated vesicle fusing with endosome Exocytosis of vesicle contents Endosome Transcytosis To lysosome for digestion and release of contents Clathrin-coated pit Plasma membrane Ingested substance Clathrin protein (a) Clathrin-mediated endocytosis 2 1 3
  18. 18. Phagocytosis Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.13b
  19. 19. Receptor Mediated Endocytosis Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.13c
  20. 20. Passive Membrane Transport – Review Process Energy Source Example Simple diffusion Kinetic energy Movement of O2 through membrane Facilitated diffusion Kinetic energy Movement of glucose into cells Osmosis Kinetic energy Movement of H2O in & out of cells Filtration Hydrostatic pressure Formation of kidney filtrate Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
  21. 21. Active Membrane Transport – Review Process Energy Source Example Active transport of solutes ATP Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Movement of ions across membranes Exocytosis ATP Neurotransmitter secretion Endocytosis ATP White blood cell phagocytosis Fluid-phase endocytosis ATP Absorption by intestinal cells Receptor-mediated endocytosis ATP Hormone and cholesterol uptake Endocytosis via caveoli ATP Cholesterol regulation Endocytosis via coatomer vesicles ATP Intracellular trafficking of molecules
  22. 22. Membrane Potential  Voltage across a membrane  Resting membrane potential – the point where K+ potential is balanced by the membrane potential  Ranges from –20 to –200 mV  Results from Na+ and K+ concentration gradients across the membrane  Differential permeability of the plasma membrane to Na+ and K+  Steady state – potential maintained by active transport of ions Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
  23. 23. Generation and Maintenance of Membrane Potential PLAY InterActive Physiology ®: Nervous System I: The Membrane Potential Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.15
  24. 24. Cell Adhesion Molecules (CAMs)  Anchor cells to the extracellular matrix  Assist in movement of cells past one another  Rally protective white blood cells to injured or infected areas Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
  25. 25. Roles of Membrane Receptors  Contact signaling – important in normal development and immunity  Electrical signaling – voltage-regulated “ion gates” in nerve and muscle tissue  Chemical signaling – neurotransmitters bind to chemically gated channel-linked receptors in nerve and muscle tissue  G protein-linked receptors – ligands bind to a receptor which activates a G protein, causing the release of a second messenger, such as cyclic AMP Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
  26. 26. Operation of a G Protein  An extracellular ligand (first messenger), binds to a specific plasma membrane protein  The receptor activates a G protein that relays the message to an effector protein Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
  27. 27. Operation of a G Protein  The effector is an enzyme that produces a second messenger inside the cell  The second messenger activates a kinase  The activated kinase can trigger a variety of cellular responses Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
  28. 28. Operation of a G Protein First messenger (ligand) Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.16 Extracellular fluid Cytoplasm Inactive second messenger Effector (e.g., enzyme) Active second messenger (e.g., cyclic AMP) Activated (phosphorylated) kinases Cascade of cellular responses (metabolic and structural changes) Membrane receptor G protein 1 2 3 4 5 6
  29. 29. Operation of a G Protein 1 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.16 Extracellular fluid Cytoplasm First messenger (ligand) Membrane receptor
  30. 30. Operation of a G Protein Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.16 Extracellular fluid Cytoplasm First messenger (ligand) Membrane receptor G protein 1 2
  31. 31. Operation of a G Protein Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.16 Extracellular fluid Cytoplasm Effector (e.g., enzyme) First messenger (ligand) Membrane receptor G protein 1 2 3
  32. 32. Operation of a G Protein Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.16 Extracellular fluid Cytoplasm Inactive second messenger Effector (e.g., enzyme) First messenger (ligand) Active second messenger (e.g., cyclic AMP) Membrane receptor G protein 1 2 3 4
  33. 33. Operation of a G Protein Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.16 Extracellular fluid Cytoplasm Inactive second messenger Effector (e.g., enzyme) Activated (phosphorylated) kinases First messenger (ligand) Active second messenger (e.g., cyclic AMP) Membrane receptor G protein 1 2 3 4 5
  34. 34. Operation of a G Protein First messenger (ligand) Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.16 Extracellular fluid Cytoplasm Inactive second messenger Effector (e.g., enzyme) Active second messenger (e.g., cyclic AMP) Activated (phosphorylated) kinases Cascade of cellular responses (metabolic and structural changes) Membrane receptor G protein 1 2 3 4 5 6
  35. 35. Cytoplasm  Cytoplasm – material between plasma membrane and the nucleus  Cytosol – largely water with dissolved protein, salts, sugars, and other solutes Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
  36. 36. Cytoplasm  Cytoplasmic organelles – metabolic machinery of the cell  Inclusions – chemical substances such as glycosomes, glycogen granules, and pigment Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
  37. 37. Cytoplasmic Organelles  Specialized cellular compartments  Membranous  Mitochondria, peroxisomes, lysosomes, endoplasmic reticulum, and Golgi apparatus  Nonmembranous  Cytoskeleton, centrioles, and ribosomes Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
  38. 38. Mitochondria  Double membrane structure with shelf-like cristae  Provide most of the cell’s ATP via aerobic cellular respiration  Contain their own DNA and RNA Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
  39. 39. Mitochondria Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.17a, b
  40. 40. Ribosomes  Granules containing protein and rRNA  Site of protein synthesis  Free ribosomes synthesize soluble proteins  Membrane-bound ribosomes synthesize proteins to be incorporated into membranes Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
  41. 41. Endoplasmic Reticulum (ER)  Interconnected tubes and parallel membranes enclosing cisternae  Continuous with the nuclear membrane  Two varieties – rough ER and smooth ER Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
  42. 42. Endoplasmic Reticulum (ER) Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.18a, c
  43. 43. Rough (ER)  External surface studded with ribosomes  Manufactures all secreted proteins  Responsible for the synthesis of integral membrane proteins and phospholipids for cell membranes Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
  44. 44. Signal Mechanism of Protein Synthesis  mRNA – ribosome complex is directed to rough ER by a signal-recognition particle (SRP)  SRP is released and polypeptide grows into cisternae  The protein is released into the cisternae and sugar groups are added Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
  45. 45. Signal Mechanism of Protein Synthesis  The protein folds into a three-dimensional conformation  The protein is enclosed in a transport vesicle and moves toward the Golgi apparatus Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
  46. 46. Signal Mechanism of Protein Synthesis Signal sequence Signal-recognition particle (SRP) Receptor site Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.19 Cytosol Ribosomes mRNA Coatomer-coated transport vesicle Transport vesicle budding off Released glycoprotein ER cisterna ER membrane Sugar group Signal sequence Growing removed polypeptide 1 2 3 4 5
  47. 47. Signal Mechanism of Protein Synthesis Signal sequence Signal-recognition particle (SRP) Receptor site Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.19 Cytosol mRNA ER cisterna ER membrane 1
  48. 48. Signal Mechanism of Protein Synthesis Signal sequence Signal-recognition particle (SRP) Receptor site Growing Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.19 Cytosol mRNA ER cisterna ER membrane polypeptide 1 2
  49. 49. Signal Mechanism of Protein Synthesis Signal sequence Signal-recognition particle (SRP) Receptor site Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.19 Cytosol Ribosomes mRNA ER cisterna ER membrane Signal sequence Growing removed polypeptide 1 2 3
  50. 50. Signal Mechanism of Protein Synthesis Signal sequence Signal-recognition particle (SRP) Receptor site Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.19 Cytosol Ribosomes mRNA Released glycoprotein ER cisterna ER membrane Signal sequence Growing removed polypeptide 1 2 3 4
  51. 51. Signal Mechanism of Protein Synthesis Signal sequence Signal-recognition particle (SRP) Receptor site Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.19 Cytosol Ribosomes mRNA Transport vesicle budding off Released glycoprotein ER cisterna ER membrane Sugar group Signal sequence Growing removed polypeptide 1 2 3 4 5
  52. 52. Signal Mechanism of Protein Synthesis Signal sequence Signal-recognition particle (SRP) Receptor site Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.19 Cytosol Ribosomes mRNA Coatomer-coated transport vesicle Transport vesicle budding off Released glycoprotein ER cisterna ER membrane Sugar group Signal sequence Growing removed polypeptide 1 2 3 4 5
  53. 53. Smooth ER  Tubules arranged in a looping network  Catalyzes the following reactions in various organs of the body  In the liver – lipid and cholesterol metabolism, breakdown of glycogen and, along with the kidneys, detoxification of drugs  In the testes – synthesis of steroid-based hormones Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
  54. 54. Smooth ER  Catalyzes the following reactions in various organs of the body (continued)  In the intestinal cells – absorption, synthesis, and transport of fats  In skeletal and cardiac muscle – storage and release of calcium Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings

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