1. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings PowerPoint ® Lecture Presentations for Biology Eighth Edition Neil Campbell and Jane Reece Lectures by Chris Romero, updated by Erin Barley with contributions from Joan Sharp Chapter 6 A Tour of the Cell

2. Learning Target 1.Distinguish between the following pairs of terms: prokaryotic and eukaryotic cell; free and bound ribosomes; smooth and rough ER 2.Describe the structure and function of the components of the endomembrane system 3.Briefly explain the role of mitochondria, chloroplasts, and peroxisomes 4.Describe the functions of the cytoskeleton Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

3. 5.Describe the structure of a plant cell wall 6.Describe the structure and roles of the extracellular matrix in animal cells Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Learning Target

4. Comparing Prokaryotic and Eukaryotic Cells Basic features of all cells: – Plasma membrane – Semifluid substance called cytosol – Chromosomes (carry genes) – Ribosomes (make proteins) Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

5. – No nucleus – DNA in an unbound region called the nucleoid – No membrane-bound organelles – Cytoplasm bound by the plasma membrane – Bacteria cells Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Prokaryotic cells are characterized by having

6. Fimbriae Nucleoid Ribosomes Plasma membrane Cell wall Capsule Flagella Bacterial chromosome A typical rod-shaped bacterium A thin section through the bacterium Bacillus coagulans (TEM) 0.5 µm Comparing Prokaryotic and Eukaryotic Cells

7. – DNA in a nucleus that is bounded by a membranous nuclear envelope – Membrane-bound organelles – Cytoplasm in the region between the plasma membrane and nucleus Eukaryotic cells are generally much larger than prokaryotic cells Animal, plant, protist, and fungi cells Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Eukaryotic cells are characterized by having

8. is a selective barrier that allows sufficient passage of oxygen, nutrients, and waste to service the volume of every cell It is a double layer of phospholipids Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Plasma Membrane

9. TEM of a plasma membrane Structure of the plasma membrane Outside of cell Inside of cell 0.1 µm Hydrophilic region Hydrophobic region Hydrophilic region PhospholipidProteins Carbohydrate side chain

10. The logistics of carrying out cellular metabolism sets limits on the size of cells The surface area to volume ratio of a cell is critical As the surface area increases by a factor of n 2, the volume increases by a factor of n 3 Small cells have a greater surface area relative to volume Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

11. Surface area increases while total volume remains constant 5 1 1 6 150750 125 1 6 6 1.2 Total surface area [Sum of the surface areas (height  width) of all boxes sides  number of boxes] Total volume [height  width  length  number of boxes] Surface-to-volume (S-to-V) ratio [surface area ÷ volume]

12. A Panoramic View of the Eukaryotic Cell A eukaryotic cell has internal membranes that partition the cell into organelles Plant and animal cells have most of the same organelles BioFlix: Tour Of An Animal Cell BioFlix: Tour Of An Animal Cell BioFlix: Tour Of A Plant Cell BioFlix: Tour Of A Plant Cell Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

13. ENDOPLASMIC RETICULUM (ER) Smooth ERRough ER Flagellum Centrosome CYTOSKELETON: Microfilaments Intermediate filaments Microtubules Microvilli Peroxisome Mitochondrion Lysosome Golgi apparatus Ribosomes Plasma membrane Nuclear envelope Nucleolus Chromatin NUCLEUS

14. Nuclear envelope Nucleolus Chromatin Rough endoplasmic reticulum Smooth endoplasmic reticulum Ribosomes Central vacuole Microfilaments Intermediate filaments Microtubules CYTO- SKELETON Chloroplast Plasmodesmata Wall of adjacent cell Cell wall Plasma membrane Peroxisome Mitochondrion Golgi apparatus

15. The Nucleus contains most of the cell’s genes and is usually the most conspicuous organelle The nuclear envelope encloses the nucleus, separating it from the cytoplasm and is a double membrane; each membrane consists of a lipid bilayer Pores regulate the entry and exit of molecules from the nucleus Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

16. DNA and proteins form genetic material called chromatin Chromatin condenses to form discrete chromosomes The nucleolus is located within the nucleus and is the site of ribosomal RNA (rRNA) synthesis Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings The Nucleus

17. Nucleolus Nucleus Rough ER Nuclear lamina (TEM) Close-up of nuclear envelope 1 µm 0.25 µm Ribosome Pore complex Nuclear pore Outer membrane Inner membrane Nuclear envelope: Chromatin Surface of nuclear envelope Pore complexes (TEM) The Nucleus

18. Ribosomes are particles made of ribosomal RNA and protein carry out protein synthesis in two locations: – In the cytosol (free ribosomes) – On the outside of the endoplasmic reticulum or the nuclear envelope (bound ribosomes) Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

19. Endomembrane system Components: – Nuclear envelope – Endoplasmic reticulum – Golgi apparatus – Lysosomes – Vacuoles – Plasma membrane These components are either continuous or connected via transfer by vesicles Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

20. The Endoplasmic Reticulum (ER) accounts for more than half of the total membrane in many eukaryotic cells The membrane is continuous with the nuclear envelope Two distinct regions of ER: – Smooth ER, which lacks ribosomes – Rough ER, with ribosomes studding its surface Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

21. Smooth ER Rough ER Nuclear envelope Transitional ER Rough ER Smooth ER Transport vesicle Ribosomes Cisternae ER lumen 200 nm

22. Functions of Smooth ER Synthesizes lipids Metabolizes carbohydrates Detoxifies poison Stores calcium Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Functions of Rough ER Has bound ribosomes, which secrete glycoproteins Distributes transport vesicles, proteins surrounded by membranes Is a membrane factory for the cell

23. consists of flattened membranous sacs called cisternae Functions: – Modifies products of the ER – Manufactures certain macromolecules – Sorts and packages materials into transport vesicles The Golgi Apparatus Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

24. cis face (“receiving” side of Golgi apparatus) Cisternae trans face (“shipping” side of Golgi apparatus) TEM of Golgi apparatus 0.1 µm The Golgi Apparatus

25. Lysosomes A sac of hydrolytic enzymes that can digest proteins, fats, polysaccharides, and nucleic acids Some types of cell can engulf another cell by phagocytosis; this forms a food vacuole A lysosome fuses with the food vacuole and digests the molecules Use enzymes to recycle the cell’s own organelles and macromolecules, called autophagy Animation: Lysosome Formation Animation: Lysosome Formation Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

26. Nucleus 1 µm Lysosome Digestive enzymes Lysosome Plasma membrane Food vacuole Phagocytosis Digestion Autophagy Peroxisome Vesicle Lysosome Mitochondrion Peroxisome fragment Mitochondrion fragment Vesicle containing two damaged organelles 1 µm Digestion Lysosomes: Digestive Compartments

27. A plant cell or fungal cell may have one or several vacuoles Food vacuoles are formed by phagocytosis Contractile vacuoles, found in many freshwater protists, pump excess water out of cells Central vacuoles, found in many mature plant cells, hold organic compounds and water Video: Paramecium Vacuole Video: Paramecium Vacuole Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Vacuoles

28. Smooth ER Nucleus Rough ER Plasma membrane

29. Smooth ER Nucleus Rough ER Plasma membrane cis Golgi trans Golgi

30. Smooth ER Nucleus Rough ER Plasma membrane cis Golgi trans Golgi

31. Mitochondria and Chloroplasts Change energy from one form to another Mitochondria, sites of cellular respiration, a metabolic process that generates ATP Chloroplasts, found in plants and algae, are the sites of photosynthesis Are not part of the endomembrane system Have a double membrane Contain their own DNA Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

32. Mitochondria in nearly all eukaryotic cells have a smooth outer membrane and an inner membrane folded into cristae The inner membrane creates two compartments: intermembrane space and mitochondrial matrix Some metabolic steps of cellular respiration are catalyzed in the mitochondrial matrix Cristae present a large surface area for enzymes that synthesize ATP Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

33. Free ribosomes in the mitochondrial matrix Intermembrane space Outer membrane Inner membrane Cristae Matrix 0.1 µm Mitochondria

34. Chloroplasts a member of a family of organelles called plastids contain the green pigment chlorophyll, as well as enzymes and other molecules that function in photosynthesis found in leaves and other green organs of plants and in algae Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

35. Ribosomes Thylakoid Stroma Granum Inner and outer membranes 1 µm Stroma, the internal fluid Chloroplast structure includes Thylakoids, membranous sacs, stacked to form a granum

36. Peroxisomes specialized metabolic compartments bounded by a single membrane produce hydrogen peroxide and convert it to water Oxygen is used to break down different types of molecules Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

37. 5 µm Macrophage Destroying Bacteria

38. Which of these organelles are absent in plant cells? A) mitochondria B) centrioles C) peroxisomes D) all of the above E) none of the above

39. Which of these organelles are absent in plant cells? A) mitochondria B) centrioles C) peroxisomes D) all of the above E) none of the above

40. A membrane protein synthesized in the rough ER may be directed to A) peroxisomes. B) lysosomes. C) mitochondria. D) all of the above

41. A membrane protein synthesized in the rough ER may be directed to A) peroxisomes. B) lysosomes. C) mitochondria. D) all of the above

42. Brefeldin A is a drug that disrupts transport from the ER to the Golgi apparatus. What other organelles and membranes are affected? A) lysosomes, vacuoles, plasma membrane B) lysosomes, peroxisomes, plasma membrane C) vacuoles, mitochondria, plasma membrane D) lysosomes, vacuoles, nuclear membrane E) all intracellular organelles and membranes

43. Brefeldin A is a drug that disrupts transport from the ER to the Golgi apparatus. What other organelles and membranes are affected? A) lysosomes, vacuoles, plasma membrane B) lysosomes, peroxisomes, plasma membrane C) vacuoles, mitochondria, plasma membrane D) lysosomes, vacuoles, nuclear membrane E) all intracellular organelles and membranes

44. The difference in the structures of animal cell extracellular matrix and plant cell walls reflects what fundamental difference(s) in their adaptive strategies? A) Animal cells must move more than plant cells. B) Animal cells have to be more responsive to changes in their environment. C) Animal cells have to communicate with each other more than plant cells. D) all of the above

45. The difference in the structures of animal cell extracellular matrix and plant cell walls reflects what fundamental difference(s) in their adaptive strategies? A) Animal cells must move more than plant cells. B) Animal cells have to be more responsive to changes in their environment. C) Animal cells have to communicate with each other more than plant cells. D) all of the above