Chapter 4 A Tour of the Cell

Transcription

1 Chapter 4 A Tour of the Cell PowerPoint Lectures Campbell Biology: Concepts & Connections, Eighth Edition REECE TAYLOR SIMON DICKEY HOGAN Lecture by Edward J. Zalisko

2 Figure Chapter 4 Objectives: You will Compare the different types of microscopes Identify where the genetic instructions are located Differentiate the endomembrane systems functions Contrast energy harvesting and processing Categorize the structural and connective components

3 INTRODUCTION TO THE CELL

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5 Figure 4.1a Light micrograph of a protist, Paramecium

6 Figure 4.1b Scanning electron micrograph of Paramecium

7 Figure 4.1c Transmission electron micrograph of Toxoplasma

8 Figure 4.1d Differential interference contrast micrograph of Paramecium

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10 Cell Theory All living things are composed of cells and that all cells come from other cells

11 Electron microscope Light microscope Unaided eye Figure 4.1e-0 10 m 1 m 100 mm (10 cm) Human height Length of some nerve and muscle cells Chicken egg 10 mm (1 cm) 1 mm 100 μm Frog egg Paramecium Human egg 10 μm 1 μm Most plant and animal cells Nucleus Most bacteria Mitochondrion 100 nm 10 nm 1 nm 0.1 nm Smallest bacteria Viruses Ribosome Proteins Lipids Small molecules Atoms

12 Table 4-1

13 ent/cells/scale/

14 Figure 4.2a Total volume Total surface area Surface-tovolume ratio 27 units 3 27 units 3 54 units units 2 2 6

15 4.2 The small size of cells fulfills the need to exchange materials across the plasma membrane Protein channels allow ions and hydrophilic molecules to pass through the hydrophobic center of the membrane. Protein pumps use energy to actively transport molecules into or out of the cell.

16 Skin cells

17 Extracellular matrix Plasma membrane

18 Figure 4.2b Outside cell Hydrophilic heads Hydrophobic tails Phospholipid Inside cell Channel protein Hydrophilic regions of a protein Hydrophobic regions of a protein

19 Figure PRIMARY STRUCTURE + H 3 N Amino end Peptide bonds connect amino acids. Amino acids Two types of SECONDARY STRUCTURES Alpha helix Secondary structures are maintained by hydrogen bonds between atoms of the backbone. TERTIARY STRUCTURE Beta pleated sheet Tertiary structure is stabilized by interactions between R groups. QUATERNARY STRUCTURE Polypeptides are associated into a functional protein.

20 4.3 Prokaryotic cells are structurally simpler than eukaryotic cells Bacteria and archaea are prokaryotic cells. smaller and simpler in structure. All other forms of life are eukaryotic cells. membrane-enclosed nucleus and organelles

21 Figure Fimbriae Ribosomes Nucleoid Bacterial chromosome A typical rod-shaped bacterium Plasma membrane Cell wall Capsule Flagella A colorized TEM of the bacterium Escherichia coli

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23 Figure 4.4a Rough endoplasmic reticulum Ribosomes NUCLEUS Nuclear envelope Nucleolus Chromatin CYTOSKELETON Microtubule Microfilament Intermediate filament Smooth endoplasmic reticulum Peroxisome Plasma membrane Golgi apparatus Lysosome Mitochondrion Centrosome with pair of centrioles

24 Figure 4.4b Smooth endoplasmic reticulum Mitochondrion Rough endoplasmic reticulum NUCLEUS Nuclear envelope Nucleolus Chromatin CYTOSKELETON Microfilament Microtubule Cell wall of adjacent cell Ribosomes Plasmodesma Golgi apparatus Peroxisome Central vacuole Chloroplast Cell wall Plasma membrane

25 Animal Cell Video

26 Plant Cell Video

27 These may look like holly berries, but they are in fact white fat cells colored red. Fat cells are some of the largest cells in the body and can grow to be about the same diameter as a human hair (i.e., 100 micrometers). Fat cells are essential as they store and release energy, protect major organs, and provide insulation from the cold. But it turns out that they also produce hormones and other substances that affect our health and this is particularly true of fat cells around the midsection. Having excess belly fat can disrupt the normal balance of hormones and increase the risks of heart disease, diabetes, and even certain types of cancer. A balanced diet combined with exercise is essential even during the holidays... Technical Details: Fat tissue was taken from a mouse that had been genetically engineered to make its blood vessels glow green under fluorescent light and treated with a dye (LipidTox Red) that turns fat red. To reveal the 3D architecture of the fat tissue computer software was used to piece together approximately 200 images taken across the depth of intact tissue using a confocal and twophoton microscope. Credit: Daniela Malide MD, PhD, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD

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29 You should now be able to 1. Describe the importance of microscopes in understanding cell structure and function. 2. Describe the two parts of cell theory. 3. Distinguish between the structures of prokaryotic and eukaryotic cells. 4. Explain how cell size is limited. 5. Describe the structure and functions of cell membranes.

30 THE NUCLEUS AND RIBOSOMES

31 Figure Chapter 4 Objectives: You will Compare the different types of microscopes Identify where the genetic instructions are located Differentiate the endomembrane systems functions Contrast energy harvesting and processing Categorize the structural and connective components

32 Figure 4.5 Nuclear envelope Nucleolus Endoplasmic reticulum Ribosome Pore Chromatin

33 Figure 4.6 Rough ER Bound ribosome Endoplasmic reticulum Protein Ribosome Free ribosome mrna

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35 Skin cells

36 Nucleus Nuclear envelope Nuclear pore

37 Nuclear Pore ship-rings

38 Protein DNA

39 Protein (enzyme) involved in making mrna DNA mrna

40 Cytoplasm mrna Nuclear pore Nuclear envelope

41 mrna Protein Ribosome

42 Protein inside compartment

43 Figure Gene DNA Transcription Nucleic acids RNA Amino acid Translation Protein

44 THE ENDOMEMBRANE SYSTEM

45 Figure Chapter 4 Objectives: You will Compare the different types of microscopes Identify where the genetic instructions are located Differentiate the endomembrane systems functions Contrast energy harvesting and processing Categorize the structural and connective components

46 4.7 Many organelles are connected in the endomembrane system nuclear envelope, endoplasmic reticulum (ER), Golgi apparatus, lysosomes, vacuoles, and plasma membrane.

47 Figure 4.8a Rough ER Smooth ER Ribosomes Rough ER Smooth ER

48 Figure 4.8b Synthesis and packaging of a secretory protein by the rough ER mrna Bound ribosome Transport vesicle buds off 4 Secretory protein inside transport vesicle 3 1 Sugar chain Growing polypeptide 2 Glycoprotein Rough ER

49 Figure 4.9 Receiving side of Golgi apparatus Transport vesicle from the ER Golgi apparatus 4 Transport vesicle from the Golgi Shipping side of Golgi apparatus

50 Animation: Lysosome Formation

51 Figure 4.10a-1 Lysosome fusing with a food vacuole and digesting food Digestive enzymes Lysosome Plasma membrane

52 Figure 4.10a-2 Digestive enzymes Lysosome Food vacuole Plasma membrane

53 Figure 4.10a-3 Digestive enzymes Lysosome Food vacuole Plasma membrane

54 Figure 4.10a-4 Digestive enzymes Lysosome Digestion Food vacuole Plasma membrane

55 Figure 4.10b-1 Lysosome fusing with a vesicle containing a damaged organelle and digesting and recycling its contents Lysosome Vesicle containing damaged mitochondrion

56 Figure 4.10b-2 Lysosome Vesicle containing damaged mitochondrion

57 Figure 4.10b-3 Lysosome Vesicle containing Digestion damaged mitochondrion

58 Skin cells

59 Smooth ER Rough ER Ribosomes

60 Protein being made inside ER mrna outside ER Ribosome outside ER Interior of rough ER

61 Vesicle Rough ER

62 Golgi apparatus Vesicle

63 Protein inside Golgi apparatus

64 Vesicle Cytoskeleton Golgi apparatus

65 Vesicle Plasma membrane Proteins

66 Lysosome Damaged mitochondrion

67 ATPs

68 Video: Paramecium Vacuole

69 Figure 4.4b Smooth endoplasmic reticulum Mitochondrion Rough endoplasmic reticulum NUCLEUS Nuclear envelope Nucleolus Chromatin CYTOSKELETON Microfilament Microtubule Cell wall of adjacent cell Ribosomes Plasmodesma Golgi apparatus Peroxisome Central vacuole Chloroplast Cell wall Plasma membrane

70 Figure 4.11a Contractile vacuoles in Paramecium, a single-celled organism Contractile vacuoles Nucleus

71 Figure 4.11b Central vacuole Chloroplast Nucleus

72 Central vacuole

73 Figure 4.12 Nucleus Smooth ER Rough ER Nuclear envelope Golgi apparatus Transport vesicle Plasma membrane Lysosome Transport vesicle

74 You should now be able to 6. Explain why compartmentalization is important in eukaryotic cells. 7. Compare the structures of plant and animal cells. Note the function of each cell part.

75 ENERGY-CONVERTING ORGANELLES

76 Figure Chapter 4 Objectives: You will Compare the different types of microscopes Identify where the genetic instructions are located Differentiate the endomembrane systems functions Contrast energy harvesting and processing Categorize the structural and connective components

77 Figure 4.13 Mitochondrion Intermembrane space Outer membrane Inner membrane Crista Matrix

78 Mitochondrion Inner membrane Outer membrane ATP

79 Mitochondrion Chloroplast ATP

80 Figure 4.14 Chloroplast Granum Stroma Inner and outer membranes Thylakoid

81 Chloroplast

82 Light Green disks Outer membrane of chloroplast Inner membrane of chloroplast

83 Sugar molecules

84 Technical details: Different color stains were used to see various structures in the plant cells: nuclei (colored red/cyan/white), cell walls (colored green), and chloroplasts (colored yellow). The stained plants were sectioned and viewed using a confocal microscope. Credit: Fernan Federici, PhD, Departamento de Genética Molecular y Microbiologia, Universidad Católica de Chile, Chile and Jim Haseloff, PhD, Department of Plant Sciences, University of Cambridge, UK

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86 4.15 EVOLUTION CONNECTION: Mitochondria and chloroplasts evolved by endosymbiosis Page 64. Read for 5 minutes and be prepared to discuss.

87 Figure Endoplasmic reticulum Nucleus Ancestor of eukaryotic cells (host cell)

88 Figure Endoplasmic reticulum Nucleus Ancestor of eukaryotic cells (host cell) Engulfing of oxygenusing prokaryote Mitochondrion Nonphotosynthetic eukaryote

89 Figure Endoplasmic reticulum Nucleus Ancestor of eukaryotic cells (host cell) Engulfing of oxygenusing prokaryote Engulfing of photosynthetic prokaryote Mitochondrion Mitochondrion At least one cell Nonphotosynthetic eukaryote Chloroplast Photosynthetic eukaryote

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91 You should now be able to 6. Compare the structures and functions of chloroplasts and mitochondria. 7. Describe the evidence that suggests that mitochondria and chloroplasts evolved by endosymbiosis.

92 THE CYTOSKELETON AND CELL SURFACES

93 Figure Chapter 4 Objectives: You will Compare the different types of microscopes Identify where the genetic instructions are located Differentiate the endomembrane systems functions Contrast energy harvesting and processing Categorize the structural and connective components

94 Figure 4.0-1

95 Video: Cytoplasmic Streaming

96 Figure Nucleus 25 nm Microtubule

97 Figure Nucleus 10 nm Intermediate filament

98 Figure nm Microfilament

99 Figure PRIMARY STRUCTURE + H 3 N Amino end Peptide bonds connect amino acids. Amino acids Two types of SECONDARY STRUCTURES Alpha helix Secondary structures are maintained by hydrogen bonds between atoms of the backbone. TERTIARY STRUCTURE Beta pleated sheet Tertiary structure is stabilized by interactions between R groups. QUATERNARY STRUCTURE Polypeptides are associated into a functional protein.

100 Figure Nucleus Nucleus 25 nm Intermediate filament 10 nm Microfilament 7 nm Microtubule

101 Skin cells

102 Cytoskeleton Microtubule Intermediate filament Microfilament

103 Figure 4.17 A fluorescence micrograph of the cytoskeleton (microtubules are green, microfilaments are red)

104 Video: Paramecium Cilia

105 Video: Chlamydomonas

106 Figure 4.18a Cilia

107 Figure 4.18b Flagellum

108 Based on the next three slides, come up with a hypothesis to explain the movement of the spindle fibers

109 Figure 4.UN04-0 Poles of dividing cell Mark

110 Figure 4.UN04-1 Poles of dividing cell Mark

111 Figure 4.UN04-2

112 4.18 Cilia and flagella move by dynein feet proteins. attach to and exert a sliding force on an adjacent doublet. This walking causes the microtubules to bend.

113 4.18 Cilia and flagella move when microtubules bend A flagellum, longer than cilia, propels a cell by an undulating, whiplike motion. Cilia work more like the oars of a boat. microtubules wrapped in an extension of the plasma membrane

114 Animation: Cilia and Flagella

115 Figure 4.18c-0 Outer microtubule doublet Central microtubules Cross-linking proteins Motor proteins (dyneins) Plasma membrane

116 Cells with many cilia on their surface, or multiciliated cells, have ancient evolutionary origins. In mammals, these cells serve essential functions, such as moving mucus in the airway, circulating cerebrospinal fluids, and moving maturing eggs and sperm along the reproductive tract. Curiously, multiciliated cells (shown here in red) are also found on the external surface of a developing tadpole. Because of their location, tadpole cilia are easy to see and manipulate, providing an outstanding experimental system for studying cilia assembly and function. Technical Details: Different color stains were used to see various structures in the tadpole tissue: actin, which reveals cell outlines is colored green, and microtubules, the core structural protein of cilia, are colored red. The stained tissues were viewed using a confocal microscope. Credit: HHMI Investigator John Wallingford PhD, Dept. Molecular Biosciences, University of Texas at Austin, Texas

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118 Figure 4.19 Glycoprotein complex with long polysaccharide Collagen fiber EXTRACELLULAR FLUID Connecting glycoprotein Integrin Plasma membrane Microfilaments of cytoskeleton CYTOPLASM

119 Figure 4.20 Tight junctions prevent fluid from moving across a layer of cells Tight junction Anchoring junction Gap junction Plasma membranes of adjacent cells Ions or small molecules Extracellular matrix

120 Animation: Desmosomes

121 Animation: Gap Junctions

122 Animation: Tight Junctions

123 Figure 4.21 Plant cell walls Vacuole Plasmodesmata Primary cell wall Secondary cell wall Plasma membrane Cytosol

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126 Underside of leaf Stoma

127 Interior of leaf Plant cell

128 Cell wall Cellulose fibril

129 Table

130 Table

131 ent/cells/insideacell/

132 You should now be able to 10. Compare the structures and functions of microfilaments, intermediate filaments, and microtubules. 11. Relate the structure of cilia and flagella to their functions. 12. Relate the structure of the extracellular matrix to its functions. 13. Compare the structures and functions of tight junctions, anchoring junctions, and gap junctions.

133 You should now be able to 14. Relate the structures of plant cell walls and plasmodesmata to their functions. 15. Describe the four functional categories of organelles in eukaryotic cells.

134 Figure 4.UN03 a. b. c. d. e. f. g. h. i. l. k. j.

135 Chapter 4 A Tour of the Cell Clicker Questions for Campbell Biology: Concepts & Connections, Eighth Edition REECE TAYLOR SIMON DICKEY HOGAN Updated by Shannon Datwyler

136 Concept Check The three domains of life described by biologists today include the bacteria, the archaea, and the eukarya (all other forms of life). What is the basic difference between the eukarya or eukaryotes and the prokaryotes (archaea and bacteria)? a) The prokaryotes do not have a plasma membrane surrounding the cell. b) The prokaryotes use RNA and not DNA to pass on the genetic message. c) The interior of the cell of eukaryotes is divided by internal membranes into specialized compartments. d) The eukaryotes engage in cellular metabolism while the prokaryotes do not.

137 Answer The three domains of life described by biologists today include the bacteria, the archaea, and the eukarya (all other forms of life). What is the basic difference between the eukarya or eukaryotes and the prokaryotes (archaea and bacteria)? a) The prokaryotes do not have a plasma membrane surrounding the cell. b) The prokaryotes use RNA and not DNA to pass on the genetic message. c) The interior of the cell of eukaryotes is divided by internal membranes into specialized compartments. d) The eukaryotes engage in cellular metabolism while the prokaryotes do not.

138 Concept Check A protein that is bound for secretion from a cell is produced a) By ribosomes floating free in the cytoplasm. b) By ribosomes within the golgi apparatus. c) By ribosomes found on the rough endoplasmic reticulum. d) By ribosomes found on the smooth endoplasmic reticulum.

139 Answer A protein that is bound for secretion from a cell is produced a) By ribosomes floating free in the cytoplasm. b) By ribosomes within the apparatus. c) By ribosomes found on the rough endoplasmic reticulum. d) By ribosomes found on the smooth endoplasmic reticulum.

140 Concept Check The cell is sometimes described as a protein factory. Using the cell-as-factory analogy, which of the following accurately describes the functions of the endomembrane system? a) The ribosomes on the rough endoplasmic reticulum are analogous to a production line in a factory. b) The Golgi apparatus is analogous to the packaging and shipping department. c) The nucleus is analogous to management offices. d) All of the above.

141 Answer The cell is sometimes described as a protein factory. Using the cell-as-factory analogy, which of the following accurately describes the functions of the endomembrane system? a) The ribosomes on the rough endoplasmic reticulum are analogous to a production line in a factory. b) The Golgi apparatus is analogous to the packaging and shipping department. c) The nucleus is analogous to management offices. d) All of the above.

142 Concept Check The primary function for microfilaments inside a cell is: a) Maintaining the cell s shape. b) Movement, as a track where proteins and organelles can move. c) Movement, in the contraction of the muscle cells.

143 Answer The primary function for microtubules inside a cell is: a) Maintaining the cell s shape b) Movement, as a track where proteins and organelles can move. c) Movement, in the contraction of the muscle cells.

144 Concept Check Plant cells have a cell wall to maintain the cell shape and to give the plant structure. Animal cells lack a cell wall but still maintain an overall shape within tissues. Which of the following are responsible for this phenomenon? a) Microtubules b) Extracellular Matrix c) Tight junctions d) Anchoring junctions

145 Answer Plant cells have a cell wall to maintain the cell shape and to give the plant structure. Animal cells lack a cell wall but still maintain an overall shape within tissues. Which of the following are responsible for this phenomenon? a) Microtubules b) Extracellular Matrix c) Tight junctions d) Anchoring junctions

146 Interpreting Data The scale of life at the cellular level can be difficult to understand. The scale on this chart is logarithmic. Each line represents a factor of 10. Compared to a typical animal or plant cell (about 100 µm in diameter), how much smaller is a mitochondria? a) Mitochondria and animal cells are essentially the same size. b) The length of mitochondria is about 1/10th the diameter of an animal cell. c) The length of mitochondria is about 1/100th the diameter of an animal cell. d) The length of mitochondria is about 1/1000th the diameter of an animal cell.

147 Answer The scale of life at the cellular level can be difficult to understand. The scale on this chart is logarithmic. Each line represents a factor of 10. Compared to a typical animal or plant cell (about 100 µm in diameter), how much smaller is a mitochondria? a) Mitochondria and animal cells are essentially the same size. b) The length of mitochondria is about 1/10th the diameter of an animal cell. c) The length of mitochondria is about 1/100th the diameter of an animal cell. d) The length of mitochondria is about 1/1000th the diameter of an animal cell.

148 Interpreting Data Cells are small but molecules are even smaller. Compared to a water molecule about how many times larger is a typical animal or plant cell (about 100 µm in diameter)? a) Cells are 1 million times larger (diameter) than a water molecule. b) Cells are 100,000 times larger (diameter) than a water molecule. c) Cells are 10,000 times larger (diameter) than a water molecule. d) Cells are 1,000 times larger (diameter) than a water molecule.

149 Answer Cells are small but molecules are even smaller. Compared to a water molecule about how many times larger is a typical animal or plant cell (about 100 µm in diameter)? a) Cells are 1 million times larger (diameter) than a water molecule. b) Cells are 100,000 times larger (diameter) than a water molecule. c) Cells are 10,000 times larger (diameter) than a water molecule. d) Cells are 1,000 times larger (diameter) than a water molecule.

150 Interpreting Data Images generated by the Hubble telescope or the planetary probes like Voyager telescope give us a very limited view of the universe. Likewise, looking at cells under a light microscope is limited by the ability to resolve cellular parts. Which of the following cell parts are visible under a light microscope? a) ribosomes b) large macromolecules c) microtubules d) mitochondria just barely

151 Answer Images generated by the Hubble telescope or the planetary probes like Voyager telescope give us a very limited view of the universe. Likewise, looking at cells under a light microscope is limited by the ability to resolve cellular parts. Which of the following cell parts are visible under a light microscope? a) ribosomes b) large macromolecules c) microtubules d) mitochondria just barely

152 Biology and Society NASA has a number of research programs that are looking for evidence of life beyond the planet Earth. Recently two Mars Rovers specifically looked for evidence of liquid water as one key component for life. Do you think that these NASA programs are justified economically? Strongly A B C D E Strongly Disagree Agree

153 Biology and Society Do you think that NASA programs are justified scientifically? Strongly A B C D E Strongly Disagree Agree

154 Biology and Society Life on another planet would require extraordinary evidence to be recognized and accepted. Looking for evidence of cells might be the most compelling evidence. Do you think that eventually we will find evidence of life elsewhere in the universe? Strongly A B C D E Strongly Disagree Agree