2. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Lectures by Chris C. Romero PowerPoint ® Lectures for Essential Biology, Third Edition – Neil Campbell, Jane Reece, and Eric Simon Essential Biology with Physiology, Second Edition – Neil Campbell, Jane Reece, and Eric Simon CHAPTER 4 A Tour of the Cell- Flashcard info alternative

3. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings All other life forms are made up of one or more eukaryotic cells These are larger and more complex than prokaryotic cells Eukaryotes are distinguished by the presence of a true nucleus Eukaryotic cells are partitioned into functional compartments

4. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings A Panoramic View of Eukaryotic Cells An idealized animal cell Cytoplasmic Streaming

5. Figure 4.6b

6. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings The Plasma Membrane Would this organelle/ structure also be found in prokaryotes? If so, are there any important differences in structure or function?

7. The Plasma Membrane: A Fluid Mosaic of Lipids and Proteins The plasma membrane separates the living cell from its nonliving surroundings. The membranes of cells are composed mostly of: –Lipids –Proteins Copyright © 2007 Pearson Education, Inc. publishing as Pearson Benjamin Cummings

8. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings The plasma membrane The lipids belong to a special category called phospholipids. Phospholipids form a two-layered membrane, the phospholipid bilayer.

9. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings The plasma membrane Most membranes have specific proteins embedded in the phospholipid bilayer. Membranes also contain cholesterol wedged between the phospholipids. Carbohydrates are found on the external surface attached to phospholipids or protein.

10. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Membrane phospholipids and proteins can drift about in the plane of the membrane. This behavior leads to the description of a membrane as a fluid mosaic: –Molecules can move freely within the membrane. –A diversity of proteins exists within the membrane.

11. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Cell Surfaces Most cells secrete materials for coats of one kind or another –That are external to the plasma membrane. These extracellular coats help protect and support cells –And facilitate interactions between cellular neighbors in tissues.

12. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Animal cells have an extracellular matrix, –Which helps hold cells together in tissues and protects and supports them.

13. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings The Cell Wall Would this organelle/ structure also be found in prokaryotes? If so, are there any important differences in structure or function?

14. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Plant cells have cell walls, –Which help protect the cells, maintain their shape, and keep the cells from absorbing too much water. –Made of Cellulose and other components in plant cells –Prokaryotes’ cell wall performs the same function, though it is composed of different organic molecules

15. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Cell Junctions –“Tunnels” that Connects the cytoplasm of one plant cell with the cytoplasm of another plant cell, thus allowing small substances to move from cell to cell. –There are other types of junctions, but that is for Advanced bio I Ex: cell Junctions

16. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings The Nucleus Would this organelle/ structure also be found in prokaryotes?

17. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings The Nucleolus

18. Figure 4.8

19. The Nucleus and Ribosomes: Genetic Control of the Cell The nucleus is the manager of the cell –Genes in the nucleus store information necessary to produce proteins which direct the cell’s activities It is usually the largest organelle. It contains chromatin (DNA) The nucleus is separated from the cytoplasm by the nuclear envelope. Copyright © 2007 Pearson Education, Inc. publishing as Pearson Benjamin Cummings

20. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Structure and Function of the Nucleolus The nucleolus is found within the nucleus –It is a mass of fibers and granules –It is where ribosomes are made

21. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Ribosomes Would this organelle/ structure also be found in prokaryotes? If so, are there any important differences in structure or function?

22. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Ribosomes Ribosomes are responsible for protein synthesis. DNA controls the cell by transferring its coded information into RNA. –The information in the RNA is used by ribosomes to make proteins.

23. The Endomembrane System: Manufacturing and Distributing Cellular Products The endomembrane system is a collection of membranous organelles These organelles manufacture and distribute cell products The endomembrane system divides the cell into compartments Copyright © 2007 Pearson Education, Inc. publishing as Pearson Benjamin Cummings

24. Figure 4.10

25. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings The Endoplasmic Reticulum The endoplasmic reticulum (ER) –Produces an enormous variety of molecules. –Is composed of smooth and rough ER.

26. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Rough Endoplasmic Reticulum

27. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Rough ER makes membrane and proteins The “roughness” of the rough ER is due to ribosomes that stud the outside of the ER membrane. The functions of the rough ER include: –Producing two types of membrane proteins –Producing new membrane

28. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Rough Endoplasmic REticulum After the rough ER synthesizes a molecule, it packages the molecule into transport vesicles. 1 2 3 4Transport vesicle buds off Ribosome Sugar chain Glycoprotein Secretory (glyco-) protein inside transport vesicle ROUGH ER Polypeptide

29. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Smooth Endoplasmic Reticulum

30. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Smooth ER Continuous with the rough ER Lacks the surface ribosomes of ER Produces lipids, including steroids. –For example how cells in your ovaries or testes produce steroid based sex hormones like estrogen and testosterone In some cells, it regulates carbohydrate metabolism In liver cells breaks down toxins and drugs –Antibiotics, barbiturates, alcohol In other cells- especially muscle cells it stores calcium ions.

31. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings The Golgi Complex

32. Figure 4.12

33. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings The Golgi Apparatus The Golgi apparatus –Works in partnership with the ER. –It consists of stacks of membranous sacs –Refines, stores, and distributes the chemical products of cells.

34. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Vesicles

35. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Lysosomes A lysosome is a membrane-enclosed sac. –It contains digestive enzymes. –The enzymes break down macromolecules.

36. Figure 4.13a

37. Figure 4.13b

38. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Lysosomes have several types of digestive functions. –They fuse with food vacuoles to digest the food. –They break down damaged organelles. Lysosome Formation

39. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Lysosomal storage diseases are hereditary They interfere with other cellular functions Examples: Pompe’s disease, Tay-Sachs disease Connection: Abnormal lysosomes can cause fatal diseases

40. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Vacuoles Vacuoles are membranous sacs. –Two types are the contractile vacuoles of protists and the central vacuoles of plants. Paramecium Vacuole

41. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings The Central Vacuole

42. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Plant cells contain a large central vacuole The vacuole absorbs water, stores vital chemicals, stores waste products Vacuoles function in the general maintenance of the cell Central vacuole Nucleus Figure 4.13A

43. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Protists may have contractile vacuoles Figure 4.13B Nucleus Contractile vacuoles These pump out excess water

44. Figure 4.15

45. Chloroplasts and Mitochondria: Energy Conversion Cells require a constant energy supply to do all the work of life. This function is carried out by the chloroplasts and the mitochondria Copyright © 2007 Pearson Education, Inc. publishing as Pearson Benjamin Cummings

46. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Chloroplasts

47. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Chloroplasts Chloroplasts are found in plants and some protists. Chloroplasts are the sites of photosynthesis, the conversion of light energy to chemical energy in sugars.

48. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Mitochondria

49. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Mitochondria Mitochondria are the sites of cellular respiration, which involves the production of ATP from food molecules.

50. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Mitochondria and chloroplasts share another feature unique among eukaryotic organelles. –They contain their own DNA. The existence of separate “mini-genomes” is believed to be evidence that –Mitochondria and chloroplasts evolved from free-living prokaryotes in the distant past.

51. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Cytoskeleton

52. The Cytoskeleton: Cell Shape and Movement The cytoskeleton is an infrastructure of the cell consisting of a network of fibers. One function of the cytoskeleton is to provide mechanical support to the cell and maintain its shape. Copyright © 2007 Pearson Education, Inc. publishing as Pearson Benjamin Cummings

53. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings The Cytoskeleton The cytoskeleton can change the shape of a cell. This allows cells like amoebae to move.

54. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Flagella Would this organelle/ structure also be found in prokaryotes? If so, are there any important differences in structure or function?

55. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Cilia and Flagella Cilia and flagella are motile appendages. Flagella propel the cell in a whiplike motion. Cilia move in a coordinated back-and- forth motion.

56. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Cilia and Flagella Some cilia or flagella extend from nonmoving cells. The human windpipe is lined with cilia.