1. Chapter 6 A Tour of the Cell

3. Fig. 6-1

7. Fig. 6-2 10 m 1 m 0.1 m 1 cm 1 mm 100 µm 10 µm 1 µm 100 nm 10 nm 1 nm 0.1 nm Atoms Small molecules Lipids Proteins Ribosomes Viruses Smallest bacteria Mitochondrion Nucleus Most bacteria Most plant and animal cells Frog egg Chicken egg Length of some nerve and muscle cells Human height Unaided eye Light microscope Electron microscope

9. Fig. 6-3 TECHNIQUE RESULTS (a) Brightfield (unstained specimen) (b) Brightfield (stained specimen) 50 µm (c) Phase-contrast (d) Differential-interference- contrast (Nomarski) (e) Fluorescence (f) Confocal 50 µm 50 µm

10. Fig. 6-3ab (a) Brightfield (unstained specimen) (b) Brightfield (stained specimen) TECHNIQUE RESULTS 50 µm

11. Fig. 6-3cd (c) Phase-contrast (d) Differential-interference- contrast (Nomarski) TECHNIQUE RESULTS

12. Fig. 6-3e (e) Fluorescence TECHNIQUE RESULTS 50 µm

13. Fig. 6-3f (f) Confocal TECHNIQUE RESULTS 50 µm

15. Fig. 6-4 (a) Scanning electron microscopy (SEM) TECHNIQUE RESULTS (b) Transmission electron microscopy (TEM) Cilia Longitudinal section of cilium Cross section of cilium 1 µm 1 µm

17. Fig. 6-5 Homogenization TECHNIQUE Homogenate Tissue cells 1,000 g (1,000 times the force of gravity) 10 min Differential centrifugation Supernatant poured into next tube 20,000 g 20 min 80,000 g 60 min Pellet rich in nuclei and cellular debris Pellet rich in mitochondria (and chloro- plasts if cells are from a plant) Pellet rich in “ microsomes” (pieces of plasma membranes and cells’ internal membranes) 150,000 g 3 hr Pellet rich in ribosomes

18. Fig. 6-5a Homogenization Homogenate Differential centrifugation Tissue cells TECHNIQUE

19. Fig. 6-5b 1,000 g (1,000 times the force of gravity) 10 min Supernatant poured into next tube 20,000 g 20 min 80,000 g 60 min 150,000 g 3 hr Pellet rich in nuclei and cellular debris Pellet rich in mitochondria (and chloro-plasts if cells are from a plant) Pellet rich in “microsomes” (pieces of plasma membranes and cells’ internal membranes) Pellet rich in ribosomes TECHNIQUE (cont.)

23. Fig. 6-6 Fimbriae Nucleoid Ribosomes Plasma membrane Cell wall Capsule Flagella Bacterial chromosome (a) A typical rod-shaped bacterium (b) A thin section through the bacterium Bacillus coagulans (TEM) 0.5 µm

26. Fig. 6-7 TEM of a plasma membrane (a) (b) Structure of the plasma membrane Outside of cell Inside of cell 0.1 µm Hydrophilic region Hydrophobic region Hydrophilic region Phospholipid Proteins Carbohydrate side chain

28. Fig. 6-8 Surface area increases while total volume remains constant 5 1 1 6 150 750 125 125 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]

30. Fig. 6-9a ENDOPLASMIC RETICULUM (ER) Smooth ER Rough ER Flagellum Centrosome CYTOSKELETON: Microfilaments Intermediate filaments Microtubules Microvilli Peroxisome Mitochondrion Lysosome Golgi apparatus Ribosomes Plasma membrane Nuclear envelope Nucleolus Chromatin NUCLEUS

31. Fig. 6-9b NUCLEUS 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

34. Fig. 6-10 Nucleolus Nucleus Rough ER Nuclear lamina (TEM) Close-up of nuclear envelope 1 µm 1 µm 0.25 µm Ribosome Pore complex Nuclear pore Outer membrane Inner membrane Nuclear envelope: Chromatin Surface of nuclear envelope Pore complexes (TEM)

38. Fig. 6-11 Cytosol Endoplasmic reticulum (ER) Free ribosomes Bound ribosomes Large subunit Small subunit Diagram of a ribosome TEM showing ER and ribosomes 0.5 µm

41. Fig. 6-12 Smooth ER Rough ER Nuclear envelope Transitional ER Rough ER Smooth ER Transport vesicle Ribosomes Cisternae ER lumen 200 nm

45. Fig. 6-13 cis face (“receiving” side of Golgi apparatus) Cisternae trans face (“shipping” side of Golgi apparatus) TEM of Golgi apparatus 0.1 µm

48. Fig. 6-14 Nucleus 1 µm Lysosome Digestive enzymes Lysosome Plasma membrane Food vacuole (a) Phagocytosis Digestion (b) Autophagy Peroxisome Vesicle Lysosome Mitochondrion Peroxisome fragment Mitochondrion fragment Vesicle containing two damaged organelles 1 µm Digestion

49. Fig. 6-14a Nucleus 1 µm Lysosome Lysosome Digestive enzymes Plasma membrane Food vacuole Digestion (a) Phagocytosis

50. Fig. 6-14b Vesicle containing two damaged organelles Mitochondrion fragment Peroxisome fragment Peroxisome Lysosome Digestion Mitochondrion Vesicle (b) Autophagy 1 µm

53. Fig. 6-15 Central vacuole Cytosol Central vacuole Nucleus Cell wall Chloroplast 5 µm

55. Fig. 6-16-1 Smooth ER Nucleus Rough ER Plasma membrane

56. Fig. 6-16-2 Smooth ER Nucleus Rough ER Plasma membrane cis Golgi trans Golgi

57. Fig. 6-16-3 Smooth ER Nucleus Rough ER Plasma membrane cis Golgi trans Golgi

61. Fig. 6-17 Free ribosomes in the mitochondrial matrix Intermembrane space Outer membrane Inner membrane Cristae Matrix 0.1 µm

64. Fig. 6-18 Ribosomes Thylakoid Stroma Granum Inner and outer membranes 1 µm

66. Fig. 6-19 1 µm Chloroplast Peroxisome Mitochondrion

68. Fig. 6-20 Microtubule Microfilaments 0.25 µm

70. Fig. 6-21 Vesicle ATP Receptor for motor protein Microtubule of cytoskeleton Motor protein (ATP powered) (a) Microtubule Vesicles (b) 0.25 µm

72. Table 6-1 10 µm 10 µm 10 µm Column of tubulin dimers Tubulin dimer Actin subunit   25 nm 7 nm Keratin proteins Fibrous subunit (keratins coiled together) 8–12 nm

73. Table 6-1a 10 µm Column of tubulin dimers Tubulin dimer   25 nm

74. Table 6-1b Actin subunit 10 µm 7 nm

75. Table 6-1c 5 µm Keratin proteins Fibrous subunit (keratins coiled together) 8–12 nm

78. Fig. 6-22 Centrosome Microtubule Centrioles 0.25 µm Longitudinal section of one centriole Microtubules Cross section of the other centriole

80. Fig. 6-23 5 µm Direction of swimming (a) Motion of flagella Direction of organism’s movement Power stroke Recovery stroke (b) Motion of cilia 15 µm

82. Fig. 6-24 0.1 µm Triplet (c) Cross section of basal body (a) Longitudinal section of cilium 0.5 µm Plasma membrane Basal body Microtubules (b) Cross section of cilium Plasma membrane Outer microtubule doublet Dynein proteins Central microtubule Radial spoke Protein cross-linking outer doublets 0.1 µm

84. Fig. 6-25 Microtubule doublets Dynein protein ATP ATP (a) Effect of unrestrained dynein movement Cross-linking proteins inside outer doublets Anchorage in cell (b) Effect of cross-linking proteins 1 3 2 (c) Wavelike motion

85. Fig. 6-25a Microtubule doublets Dynein protein (a) Effect of unrestrained dynein movement ATP

86. Fig. 6-25b Cross-linking proteins inside outer doublets Anchorage in cell ATP (b) Effect of cross-linking proteins (c) Wavelike motion 1 3 2

88. Fig. 6-26 Microvillus Plasma membrane Microfilaments (actin filaments) Intermediate filaments 0.25 µm

90. Fig. 6-27 Muscle cell Actin filament Myosin filament Myosin arm (a) Myosin motors in muscle cell contraction Cortex (outer cytoplasm): gel with actin network Inner cytoplasm: sol with actin subunits Extending pseudopodium (b) Amoeboid movement Nonmoving cortical cytoplasm (gel) Chloroplast Streaming cytoplasm (sol) Vacuole Cell wall Parallel actin filaments (c) Cytoplasmic streaming in plant cells

91. Fig, 6-27a Muscle cell Actin filament Myosin filament Myosin arm (a) Myosin motors in muscle cell contraction

92. Fig. 6-27bc Cortex (outer cytoplasm): gel with actin network Inner cytoplasm: sol with actin subunits Extending pseudopodium (b) Amoeboid movement Nonmoving cortical cytoplasm (gel) Chloroplast Cell wall Streaming cytoplasm (sol) Parallel actin filaments (c) Cytoplasmic streaming in plant cells Vacuole

99. Fig. 6-28 Secondary cell wall Primary cell wall Middle lamella Central vacuole Cytosol Plasma membrane Plant cell walls Plasmodesmata 1 µm

100. Fig. 6-29 10 µm Distribution of cellulose synthase over time Distribution of microtubules over time RESULTS

102. Fig. 6-30 EXTRACELLULAR FLUID Collagen Fibronectin Plasma membrane Micro- filaments CYTOPLASM Integrins Proteoglycan complex Polysaccharide molecule Carbo- hydrates Core protein Proteoglycan molecule Proteoglycan complex

103. Fig. 6-30a Collagen Fibronectin Plasma membrane Proteoglycan complex Integrins CYTOPLASM Micro-filaments EXTRACELLULAR FLUID

104. Fig. 6-30b Polysaccharide molecule Carbo-hydrates Core protein Proteoglycan molecule Proteoglycan complex

108. Fig. 6-31 Interior of cell Interior of cell 0.5 µm Plasmodesmata Plasma membranes Cell walls

110. Fig. 6-32 Tight junction 0.5 µm 1 µm Desmosome Gap junction Extracellular matrix 0.1 µm Plasma membranes of adjacent cells Space between cells Gap junctions Desmosome Intermediate filaments Tight junction Tight junctions prevent fluid from moving across a layer of cells

111. Fig. 6-32a Tight junctions prevent fluid from moving across a layer of cells Tight junction Intermediate filaments Desmosome Gap junctions Extracellular matrix Space between cells Plasma membranes of adjacent cells

112. Fig. 6-32b Tight junction 0.5 µm

113. Fig. 6-32c Desmosome 1 µm

114. Fig. 6-32d Gap junction 0.1 µm

116. Fig. 6-33 5 µm

117. Fig. 6-UN1 Cell Component Structure Function Houses chromosomes, made of chromatin (DNA, the genetic material, and proteins); contains nucleoli, where ribosomal subunits are made. Pores regulate entry and exit of materials. Nucleus (ER) Concept 6.3 The eukaryotic cell’s genetic instructions are housed in the nucleus and carried out by the ribosomes Ribosome Concept 6.4 Endoplasmic reticulum The endomembrane system regulates protein traffic and performs metabolic functions in the cell (Nuclear envelope) Concept 6.5 Mitochondria and chloro- plasts change energy from one form to another Golgi apparatus Lysosome Vacuole Mitochondrion Chloroplast Peroxisome Two subunits made of ribo- somal RNA and proteins; can be free in cytosol or bound to ER Extensive network of membrane-bound tubules and sacs; membrane separates lumen from cytosol; continuous with the nuclear envelope. Membranous sac of hydrolytic enzymes (in animal cells) Large membrane-bounded vesicle in plants Bounded by double membrane; inner membrane has infoldings (cristae) Typically two membranes around fluid stroma, which contains membranous thylakoids stacked into grana (in plants) Specialized metabolic compartment bounded by a single membrane Protein synthesis Smooth ER: synthesis of lipids, metabolism of carbohy- drates, Ca 2+ storage, detoxifica-tion of drugs and poisons Rough ER: Aids in synthesis of secretory and other proteins from bound ribosomes; adds carbohydrates to glycoproteins; produces new membrane Modification of proteins, carbo- hydrates on proteins, and phos- pholipids; synthesis of many polysaccharides; sorting of Golgi products, which are then released in vesicles. Breakdown of ingested substances, cell macromolecules, and damaged organelles for recycling Digestion, storage, waste disposal, water balance, cell growth, and protection Cellular respiration Photosynthesis Contains enzymes that transfer hydrogen to water, producing hydrogen peroxide (H 2 O 2 ) as a by-product, which is converted to water by other enzymes in the peroxisome Stacks of flattened membranous sacs; has polarity ( cis and trans faces) Surrounded by nuclear envelope (double membrane) perforated by nuclear pores. The nuclear envelope is continuous with the endoplasmic reticulum (ER).

118. Fig. 6-UN1a Cell Component Structure Function Concept 6.3 The eukaryotic cell’s genetic instructions are housed in the nucleus and carried out by the ribosomes Nucleus Surrounded by nuclear envelope (double membrane) perforated by nuclear pores. The nuclear envelope is continuous with the endoplasmic reticulum (ER). (ER) Houses chromosomes, made of chromatin (DNA, the genetic material, and proteins); contains nucleoli, where ribosomal subunits are made. Pores regulate entry and exit os materials. Ribosome Two subunits made of ribo- somal RNA and proteins; can be free in cytosol or bound to ER Protein synthesis

119. Fig. 6-UN1b Cell Component Structure Function Concept 6.4 The endomembrane system regulates protein traffic and performs metabolic functions in the cell Endoplasmic reticulum (Nuclear envelope) Golgi apparatus Lysosome Vacuole Large membrane-bounded vesicle in plants Membranous sac of hydrolytic enzymes (in animal cells) Stacks of flattened membranous sacs; has polarity ( cis and trans faces) Extensive network of membrane-bound tubules and sacs; membrane separates lumen from cytosol; continuous with the nuclear envelope. Smooth ER: synthesis of lipids, metabolism of carbohy- drates, Ca 2+ storage, detoxifica- tion of drugs and poisons Rough ER: Aids in sythesis of secretory and other proteins from bound ribosomes; adds carbohydrates to glycoproteins; produces new membrane Modification of proteins, carbo- hydrates on proteins, and phos- pholipids; synthesis of many polysaccharides; sorting of Golgi products, which are then released in vesicles. Breakdown of ingested sub- stances cell macromolecules, and damaged organelles for recycling Digestion, storage, waste disposal, water balance, cell growth, and protection

120. Fig. 6-UN1c Cell Component Concept 6.5 Mitochondria and chloro- plasts change energy from one form to another Mitochondrion Chloroplast Peroxisome Structure Function Bounded by double membrane; inner membrane has infoldings (cristae) Typically two membranes around fluid stroma, which contains membranous thylakoids stacked into grana (in plants ) Specialized metabolic compartment bounded by a single membrane Cellular respiration Photosynthesis Contains enzymes that transfer hydrogen to water, producing hydrogen peroxide (H 2 O 2 ) as a by-product, which is converted to water by other enzymes in the peroxisome

121. Fig. 6-UN2

122. Fig. 6-UN3