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LECTURE PRESENTATIONS For CAMPBELL BIOLOGY, NINTH EDITION Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert.

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Presentation on theme: "LECTURE PRESENTATIONS For CAMPBELL BIOLOGY, NINTH EDITION Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert."— Presentation transcript:

1 LECTURE PRESENTATIONS For CAMPBELL BIOLOGY, NINTH EDITION Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson © 2011 Pearson Education, Inc. Lectures by Erin Barley Kathleen Fitzpatrick A Tour of the Cell Chapter 6

2 Overview: The Fundamental Units of Life All organisms are made of cells The cell is the simplest collection of matter that can be alive Cell structure is correlated to cellular function All cells are related by their descent from earlier cells © 2011 Pearson Education, Inc.

3 Figure 6.1

4 Brightfield (unstained specimen) Brightfield (stained specimen) 50  m Confocal Differential-interference- contrast (Nomarski) Fluorescence 10  m Deconvolution Super-resolution Scanning electron microscopy (SEM) Transmission electron microscopy (TEM) Cross section of cilium Longitudinal section of cilium Cilia Electron Microscopy (EM) 1  m 10  m 50  m 2  m Light Microscopy (LM) Phase-contrast Figure 6.3

5 Comparing Prokaryotic and Eukaryotic Cells Basic features of all cells –Plasma membrane –Semifluid substance called cytosol –Chromosomes (carry genes) –Ribosomes (make proteins) © 2011 Pearson Education, Inc.

6 Prokaryotic cells – Archae and Bacteria –No nucleus –DNA in an unbound region called the nucleoid –No membrane-bound organelles –Cytoplasm bound by the plasma membrane © 2011 Pearson Education, Inc.

7 Fimbriae Bacterial chromosome A typical rod-shaped bacterium (a) Nucleoid Ribosomes Plasma membrane Cell wall Capsule Flagella A thin section through the bacterium Bacillus coagulans (TEM) (b) 0.5  m Figure 6.5

8 Figure 6.5a A thin section through the bacterium Bacillus coagulans (TEM) (b) 0.5  m

9 Eukaryotic cells –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 –Larger than prokaryotes © 2011 Pearson Education, Inc.

10 The plasma membrane - a selective barrier that allows sufficient passage of oxygen, nutrients, and waste to service the volume of every cell The general structure of a biological membrane is a double layer of phospholipids μm circumference © 2011 Pearson Education, Inc.

11 Figure 6.6 Outside of cell Inside of cell 0.1  m (a) TEM of a plasma membrane Hydrophilic region Hydrophobic region Hydrophilic region Carbohydrate side chains Proteins Phospholipid (b) Structure of the plasma membrane

12 Figure 6.6a Outside of cell Inside of cell 0.1  m (a) TEM of a plasma membrane

13 Surface area/volume ratio n 2 /n 3 © 2011 Pearson Education, Inc.

14 Surface area increases while total volume remains constant Total surface area [sum of the surface areas (height  width) of all box sides  number of boxes] Total volume [height  width  length  number of boxes] Surface-to-volume (S-to-V) ratio [surface area  volume] Figure 6.7

15 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 © 2011 Pearson Education, Inc.

16 Figure 6.8a ENDOPLASMIC RETICULUM (ER) Rough ER Smooth ER Nuclear envelope Nucleolus Chromatin Plasma membrane Ribosomes Golgi apparatus Lysosome Mitochondrion Peroxisome Microvilli Microtubules Intermediate filaments Microfilaments Centrosome CYTOSKELETON: Flagellum NUCLEUS

17 Figure 6.8b Animal Cells Cell Nucleus Nucleolus Human cells from lining of uterus (colorized TEM) Yeast cells budding (colorized SEM) 10  m Fungal Cells 5  m Parent cell Buds 1  m Cell wall Vacuole Nucleus Mitochondrion A single yeast cell (colorized TEM)

18 NUCLEUS Nuclear envelope Nucleolus Chromatin Golgi apparatus Mitochondrion Peroxisome Plasma membrane Cell wall Wall of adjacent cell Plasmodesmata Chloroplast Microtubules Intermediate filaments Microfilaments CYTOSKELETON Central vacuole Ribosomes Smooth endoplasmic reticulum Rough endoplasmic reticulum Figure 6.8c

19 Figure 6.8d Plant Cells Cells from duckweed (colorized TEM) Cell 5  m Cell wall Chloroplast Nucleus Nucleolus 8  m Protistan Cells 1  m Chlamydomonas (colorized SEM) Chlamydomonas (colorized TEM) Flagella Nucleus Nucleolus Vacuole Chloroplast Cell wall Mitochondrion

20 Concept 6.3: Nucleus, DNA, and Ribosomes The nucleus contains most of the DNA in a eukaryotic cell Ribosomes use the information from the DNA to make proteins 5 μm © 2011 Pearson Education, Inc.

21 The Nucleus: Information Central Nucleus - contains most of the cell’s genes and is the most conspicuous organelle nuclear envelope - encloses the nucleus, separating it from the cytoplasm A double membrane; each membrane consists of a lipid bilayer © 2011 Pearson Education, Inc.

22 Nucleus Rough ER Nucleolus Chromatin Nuclear envelope: Inner membrane Outer membrane Nuclear pore Chromatin Ribosome Pore complex Close-up of nuclear envelope Figure 6.9a

23 Figure 6.9b Nuclear envelope: Inner membrane Outer membrane Nuclear pore Surface of nuclear envelope 1  m

24 Figure 6.9c Pore complexes (TEM) 0.25  m

25 Figure 6.9d 1  m Nuclear lamina (TEM)

26 Pores- regulate the entry and exit of molecules from the nucleus The shape of the nucleus is maintained by the nuclear lamina, which is composed of protein © 2011 Pearson Education, Inc.

27 In the nucleus, DNA is organized into discrete units called chromosomes Each chromosome is composed of a single DNA molecule associated with proteins The DNA and proteins of chromosomes are together called chromatin Chromatin condenses to form discrete chromosomes as a cell prepares to divide The nucleolus is located within the nucleus and is the site of ribosomal RNA (rRNA) synthesis © 2011 Pearson Education, Inc.

28 Ribosomes: Protein Factories Ribosomes are particles made of ribosomal RNA and protein Ribosomes 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) © 2011 Pearson Education, Inc.

29 Figure  m Free ribosomes in cytosol Endoplasmic reticulum (ER) Ribosomes bound to ER Large subunit Small subunit Diagram of a ribosome TEM showing ER and ribosomes

30 Concept 6.4: The endomembrane system - regulates protein traffic and performs metabolic functions in the cell Components of the endomembrane system –Nuclear envelope –Endoplasmic reticulum –Golgi apparatus –Lysosomes –Vacuoles –Plasma membrane These components are either continuous or connected via transfer by vesicles © 2011 Pearson Education, Inc.

31 The Endoplasmic Reticulum: Biosynthetic Factory The endoplasmic reticulum (ER) accounts for more than half of the total membrane in many eukaryotic cells The ER membrane is continuous with the nuclear envelope There are two distinct regions of ER –Smooth ER, which lacks ribosomes –Rough ER, surface is studded with ribosomes © 2011 Pearson Education, Inc.

32 Figure 6.11a Smooth ER Rough ER Cisternae Ribosomes Transport vesicle Transitional ER Nuclear envelope ER lumen

33 Figure 6.11b Smooth ER Rough ER 200 nm

34 Functions of Smooth ER The smooth ER –Synthesizes lipids – sex cells and adrenal glands –Metabolizes carbohydrates –Detoxifies drugs and poisons- liver cells –Stores calcium ions - muscles © 2011 Pearson Education, Inc.

35 Functions of Rough ER The rough ER –Has bound ribosomes, which secrete glycoproteins (proteins covalently bonded to carbohydrates) –Distributes transport vesicles, proteins surrounded by membranes –Is a membrane factory for the cell © 2011 Pearson Education, Inc.

36 The Golgi apparatus consists of flattened membranous sacs called cisternae Functions of the Golgi apparatus –Modifies products of the ER – glycoproteins and phospholipids –Manufactures certain macromolecules – pectin –Sorts and packages materials into transport vesicles –molecular tagging for docking sites The Golgi Apparatus: Shipping and Receiving Center © 2011 Pearson Education, Inc.

37 Figure 6.12 cis face (“receiving” side of Golgi apparatus) trans face (“shipping” side of Golgi apparatus) 0.1  m TEM of Golgi apparatus Cisternae

38 Lysosomes: Digestive Compartments A lysosome is a membranous sac of hydrolytic enzymes that can digest macromolecules Lysosomal enzymes can hydrolyze proteins, fats, polysaccharides, and nucleic acids Lysosomal enzymes work best in the acidic environment inside the lysosome © 2011 Pearson Education, Inc.

39 Some types of cell (amoeba and white blood cells) can engulf another cell by phagocytosis; this forms a food vacuole fuses with the food vacuole and digests the molecules use enzymes to recycle the cell’s own organelles and macromolecules, a process called autophagy © 2011 Pearson Education, Inc.

40 Figure 6.13 Nucleus Lysosome 1  m Digestive enzymes Digestion Food vacuole Lysosome Plasma membrane (a) Phagocytosis Vesicle containing two damaged organelles 1  m Mitochondrion fragment Peroxisome fragment (b) Autophagy Peroxisome Vesicle Mitochondrion Lysosome Digestion

41 Figure 6.13b Vesicle containing two damaged organelles 1  m Mitochondrion fragment Peroxisome fragment Peroxisome Vesicle Mitochondrion Lysosome Digestion (b) Autophagy

42 Vacuoles: Diverse Maintenance Compartments A plant cell or fungal cell may have one or several vacuoles, derived from endoplasmic reticulum and Golgi apparatus © 2011 Pearson Education, Inc.

43 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 © 2011 Pearson Education, Inc.

44 Figure 6.14 Central vacuole Cytosol Nucleus Cell wall Chloroplast Central vacuole 5  m

45 Figure 6.14a Cytosol Nucleus Cell wall Chloroplast Central vacuole 5  m

46 Figure Smooth ER Nucleus Rough ER Plasma membrane

47 Figure Smooth ER Nucleus Rough ER Plasma membrane cis Golgi trans Golgi

48 Figure Smooth ER Nucleus Rough ER Plasma membrane cis Golgi trans Golgi

49 Concept 6.5: Mitochondria and chloroplasts change energy from one form to another Mitochondria are the sites of cellular respiration, a metabolic process that uses oxygen to generate ATP Chloroplasts, found in plants and algae, are the sites of photosynthesis Peroxisomes are oxidative organelles © 2011 Pearson Education, Inc.

50 Mitochondria and chloroplasts have similarities with bacteria –Enveloped by a double membrane –Contain free ribosomes and circular DNA molecules –Grow and reproduce somewhat independently in cells © 2011 Pearson Education, Inc. The Evolutionary Origins of Mitochondria and Chloroplasts

51 The Endosymbiont theory –An early ancestor of eukaryotic cells engulfed a nonphotosynthetic prokaryotic cell, which formed an endosymbiont relationship with its host –The host cell and endosymbiont merged into a single organism, a eukaryotic cell with a mitochondrion –At least one of these cells may have taken up a photosynthetic prokaryote, becoming the ancestor of cells that contain chloroplasts © 2011 Pearson Education, Inc.

52 Nucleus Endoplasmic reticulum Nuclear envelope Ancestor of eukaryotic cells (host cell) Engulfing of oxygen- using nonphotosynthetic prokaryote, which becomes a mitochondrion Mitochondrion Nonphotosynthetic eukaryote Mitochondrion At least one cell Photosynthetic eukaryote Engulfing of photosynthetic prokaryote Chloroplast Figure 6.16

53 Mitochondria: Chemical Energy Conversion Found in eukaryotes 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 © 2011 Pearson Education, Inc.

54 Figure 6.17 Intermembrane space Outer membrane DNA Inner membrane Cristae Matrix Free ribosomes in the mitochondrial matrix (a) Diagram and TEM of mitochondrion (b) Network of mitochondria in a protist cell (LM) 0.1  m Mitochondrial DNA Nuclear DNA Mitochondria 10  m

55 Figure 6.17a Intermembrane space Outer DNA Inner membrane Cristae Matrix Free ribosomes in the mitochondrial matrix (a) Diagram and TEM of mitochondrion 0.1  m membrane

56 Figure 6.17aa Outer membrane Inner membrane Cristae Matrix 0.1  m

57 Chloroplasts: Capture of Light Energy contain the green pigment chlorophyll contains enzymes and other molecules that function in photosynthesis found in leaves and other green organs of plants and in algae © 2011 Pearson Education, Inc.

58 Chloroplast structure includes –Thylakoids, membranous sacs, stacked to form a granum –Stroma, the internal fluid The chloroplast is one of a group of plant organelles, called plastids © 2011 Pearson Education, Inc.

59 Figure 6.18 Ribosomes Stroma Inner and outer membranes Granum 1  m Intermembrane space Thylakoid (a) Diagram and TEM of chloroplast (b) Chloroplasts in an algal cell Chloroplasts (red) 50  m DNA

60 Figure 6.18a Ribosomes Stroma Inner and outer membranes Granum 1  m Intermembrane space Thylakoid (a) Diagram and TEM of chloroplast DNA

61 Figure 6.18b (b) Chloroplasts in an algal cell Chloroplasts (red) 50  m

62 Peroxisomes: Oxidation specialized metabolic compartments bounded by a single membrane Remove H+ to O+ which produces hydrogen peroxide and convert it to water Glyoxysomes – found in plant seed and fatty acids to sugar for the cotyledon until photosynthesis begins © 2011 Pearson Education, Inc.

63 Figure 6.19 Chloroplast Peroxisome Mitochondrion 1  m

64 Concept 6.6: The cytoskeleton is a network of fibers that organizes structures and activities in the cell extends throughout the cytoplasm organizes the cell’s structures and activities, anchoring many organelles composed of three types of molecular structures –Microtubules –Microfilaments –Intermediate filaments © 2011 Pearson Education, Inc.

65 Figure  m

66 Roles of the Cytoskeleton: Support and Motility support the cell and maintain its shape It interacts with motor proteins to produce motility (flagella/cilia;muscle contraction; plasma membrane; cytostreaming Inside the cell, vesicles can travel along “monorails” provided by the cytoskeleton © 2011 Pearson Education, Inc.

67 Figure 6.21 ATP Vesicle (a) Motor protein (ATP powered) Microtubule of cytoskeleton Receptor for motor protein 0.25  m Vesicles Microtubule (b)

68 Figure 6.21a 0.25  m Vesicles Microtubule (b)

69 Components of the Cytoskeleton –Microtubules – thickest; organelle movement; secretory vesicles to plasma membrane; mitosis –Microfilaments – thinnest (also called actin) – supports cell shape; microvilli; forms bridge with myosin for muscle contraction;cell contraction during cell cleavage; pseudopodia movement (amoeba and WBC) –Intermediate filaments -diameters in a middle range – contains protein keratin; reinforces position of nucleus;nuclear lamina; axons © 2011 Pearson Education, Inc.

70 Column of tubulin dimers Tubulin dimer 25 nm   Actin subunit 7 nm Keratin proteins 8  12 nm Fibrous subunit (keratins coiled together) 10  m 5  m Table 6.1

71 Tubulin dimer 25 nm  Column of tubulin dimers 10  m Table 6.1a

72 Centrosomes and Centrioles centrosome near the nucleus; microtubules grow from it In animal cells, the centrosome has a pair of centrioles, each with nine triplets of microtubules arranged in a ring © 2011 Pearson Education, Inc.

73 Centrosome Longitudinal section of one centriole Centrioles Microtubule 0.25  m Microtubules Cross section of the other centriole Figure 6.22

74 Cilia and Flagella Microtubules control the beating of cilia and flagella, locomotor appendages of some cells Cilia and flagella differ in their beating patterns © 2011 Pearson Education, Inc.

75 Direction of swimming (b) Motion of cilia Direction of organism’s movement Power stroke Recovery stroke (a) Motion of flagella 5  m 15  m Figure 6.23

76 Cilia and flagella share a common structure –A core of microtubules sheathed by the plasma membrane –A basal body that anchors the cilium or flagellum –A motor protein called dynein, which drives the bending movements of a cilium or flagellum © 2011 Pearson Education, Inc.

77 Microtubules Plasma membrane Basal body Longitudinal section of motile cilium (a) 0.5  m 0.1  m (b) Cross section of motile cilium Outer microtubule doublet Dynein proteins Central microtubule Radial spoke Cross-linking proteins between outer doublets Plasma membrane Triplet (c) Cross section of basal body Figure 6.24

78 Figure 6.24ba 0.1  m (b) Cross section of motile cilium Outer microtubule doublet Dynein proteins Central microtubule Radial spoke Cross-linking proteins between outer doublets

79 Figure 6.24c 0.1  m Triplet (c) Cross section of basal body

80 Figure 6.24ca 0.1  m Triplet (c) Cross section of basal body

81 How dynein “walking” moves flagella and cilia − Dynein arms alternately grab, move, and release the outer microtubules –Protein cross-links limit sliding –Forces exerted by dynein arms cause doublets to curve, bending the cilium or flagellum © 2011 Pearson Education, Inc.

82 Microtubule doublets Dynein protein ATP (a) Effect of unrestrained dynein movement Figure 6.25a

83 Figure 6.25b Cross-linking proteins between outer doublets ATP Anchorage in cell (b) Effect of cross-linking proteins (c) Wavelike motion 3 1 2

84 Figure 6.27 Muscle cell Actin filament Myosin filament head (a) Myosin motors in muscle cell contraction 0.5  m 100  m Cortex (outer cytoplasm): gel with actin network Inner cytoplasm: sol with actin subunits (b) Amoeboid movement Extending pseudopodium 30  m (c) Cytoplasmic streaming in plant cells Chloroplast

85 Figure 6.27a Muscle cell Actin filament Myosin filament (a) Myosin motors in muscle cell contraction 0.5  m head

86 Figure 6.27b 100  m Cortex (outer cytoplasm): gel with actin network Inner cytoplasm: sol with actin subunits (b) Amoeboid movement Extending pseudopodium

87 Figure 6.27c 30  m (c) Cytoplasmic streaming in plant cells Chloroplast

88 Cytoplasmic streaming is a circular flow of cytoplasm within cells This streaming speeds distribution of materials within the cell In plant cells, actin-myosin interactions and sol- gel transformations drive cytoplasmic streaming © 2011 Pearson Education, Inc.

89 Concept 6.7: Extracellular components and connections between cells help coordinate cellular activities Most cells synthesize and secrete materials that are external to the plasma membrane These extracellular structures include –Cell walls of plants –The extracellular matrix (ECM) of animal cells –Intercellular junctions © 2011 Pearson Education, Inc.

90 Cell Walls of Plants an extracellular structure that distinguishes plant cells from animal cells Prokaryotes, fungi, and some protists also have cell walls The cell wall protects the plant cell, maintains its shape, and prevents excessive uptake of water Plant cell walls are made of cellulose fibers embedded in other polysaccharides and protein © 2011 Pearson Education, Inc.

91 Plant cell walls may have multiple layers –Primary cell wall: relatively thin and flexible –Middle lamella: thin layer between primary walls of adjacent cells –Secondary cell wall (in some cells): added between the plasma membrane and the primary cell wall © 2011 Pearson Education, Inc.

92 Secondary cell wall Primary cell wall Middle lamella Central vacuole Cytosol Plasma membrane Plant cell walls Plasmodesmata 1  m Figure 6.28

93 Figure 6.29 RESULTS 10  m Distribution of cellulose synthase over time Distribution of microtubules over time

94 The Extracellular Matrix (ECM) of Animal Cells Animal cells lack cell walls but are covered by an elaborate extracellular matrix (ECM) The ECM is made up of glycoproteins such as collagen, proteoglycans, and fibronectin ECM proteins bind to receptor proteins in the plasma membrane called integrins © 2011 Pearson Education, Inc.

95 Figure 6.30 EXTRACELLULAR FLUID Collagen Fibronectin Plasma membrane Micro- filaments CYTOPLASM Integrins Proteoglycan complex Polysaccharide molecule Carbo- hydrates Core protein Proteoglycan molecule Proteoglycan complex

96 Functions of the ECM –Support –Adhesion –Movement –Regulation © 2011 Pearson Education, Inc.

97 Cell Junctions Neighboring cells in tissues, organs, or organ systems often adhere, interact, and communicate through direct physical contact © 2011 Pearson Education, Inc.

98 Plasmodesmata in Plant Cells Plasmodesmata are channels that perforate plant cell walls Through plasmodesmata, water and small solutes (and sometimes proteins and RNA) can pass from cell to cell © 2011 Pearson Education, Inc.

99 Figure 6.31 Interior of cell 0.5  m Plasmodesmata Plasma membranes Cell walls

100 Tight Junctions, Desmosomes, and Gap Junctions in Animal Cells At tight junctions, membranes of neighboring cells are pressed together, preventing leakage of extracellular fluid (skin cells) Desmosomes (anchoring junctions) fasten cells together into strong sheets (muscle cells to muscle cells) Gap junctions (communicating junctions) provide cytoplasmic channels between adjacent cells – (heart) © 2011 Pearson Education, Inc.

101 Tight junctions prevent fluid from moving across a layer of cells Extracellular matrix Plasma membranes of adjacent cells Space between cells Ions or small molecules Desmosome Intermediate filaments Tight junction Gap junction Figure 6.32a

102 Figure 6.32b Tight junction TEM 0.5  m

103 Figure  m


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