Microbiology an Introduction Chapter 4 PDF

Microbiology an Introduction Thirteenth Edition Chapter 4 Functional Anatomy of Prokaryotic and Eukaryotic Cells Copyright © 2019 Pearson Education, Inc. All Rights Reserved Serratia Bacteria Copyright © 2019 Pearson Education, Inc. All Rights Reserved Comparing Prokaryotic and Eukaryotic Cells: an...

Microbiology an Introduction Thirteenth Edition Chapter 4 Functional Anatomy of Prokaryotic and Eukaryotic Cells Copyright © 2019 Pearson Education, Inc. All Rights Reserved Serratia Bacteria Copyright © 2019 Pearson Education, Inc. All Rights Reserved Comparing Prokaryotic and Eukaryotic Cells: an Overview (1 of 3) Learning Objective 4-1 Compare the cell structure of prokaryotes and eukaryotes Copyright © 2019 Pearson Education, Inc. All Rights Reserved Comparing Prokaryotic and Eukaryotic Cells: an Overview (2 of 3) Prokaryote comes from the Greek words for prenucleus. Eukaryote comes from the Greek words for true nucleus. Copyright © 2019 Pearson Education, Inc. All Rights Reserved Comparing Prokaryotic and Eukaryotic Cells: an Overview (3 of 3) Prokaryote Eukaryote One circular chromosome, not Paired chromosomes, in a membrane in nuclear membrane No histones Histones No organelles Organelles Bacteria: peptidoglycan cell Polysaccharide cell walls, walls when present Archaea: pseudomurein cell Divides by mitosis walls Divides by binary fission Copyright © 2019 Pearson Education, Inc. All Rights Reserved Check Your Understanding-1 Check Your Understanding 4-1 What is the main feature that distinguishes prokaryotes from eukaryotes? Copyright © 2019 Pearson Education, Inc. All Rights Reserved The Prokaryotic Cell Learning Objective 4-2 Identify the three basic shapes of bacteria Copyright © 2019 Pearson Education, Inc. All Rights Reserved The Size, Shape, and Arrangement of Bacterial Cells (1 of 4) Average size: 0.2 to 2.0 µm diameter ´ 2 to 8 µm length Most bacteria are monomorphic (single shape) A few are pleomorphic (many shapes) Copyright © 2019 Pearson Education, Inc. All Rights Reserved The Size, Shape, and Arrangement of Bacterial Cells (2 of 4) Bacillus (rod-shaped) Coccus (spherical-shaped) Spiral – Vibrio – Spirillum – Spirochete Star-shaped Rectangular Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-4 Spiral Bacteria For Long description, see slide 144: Appendix 1 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-5a Star-Shaped and Rectangular Prokaryotes For Long description, see slide 145: Appendix 2 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-5b Star-Shaped and Rectangular Prokaryotes For Long description, see slide 146: Appendix 3 Copyright © 2019 Pearson Education, Inc. All Rights Reserved The Size, Shape, and Arrangement of Bacterial Cells (3 of 4) Pairs: diplococci, diplobacilli Clusters: staphylococci Chains: streptococci, streptobacilli Groups of four: tetrads Cubelike groups of eight: sarcinae Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-1 Arrangements of Cocci For Long description, see slide 147: Appendix 4 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-2a-d Bacilli For Long description, see slide 148: Appendix 5 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-2b-c Bacilli For Long description, see slide 149: Appendix 6 Copyright © 2019 Pearson Education, Inc. All Rights Reserved The Size, Shape, and Arrangement of Bacterial Cells (4 of 4) Scientific name: Bacillus Shape: bacillus Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-3 Gram-Stained Bacillus Anthracis For Long description, see slide 150: Appendix 7 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Check Your Understanding-2 Check Your Understanding 4-2 How can you identify streptococci with a microscope? Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-6 The Structure of a Prokaryotic Cell For Long description, see slide 151: Appendix 8 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Structures External to the Cell Wall Learning Objectives 4-3 Describe the structure and function of the glycocalyx. 4-4 Differentiate flagella, axial filaments, fimbriae, and pili Copyright © 2019 Pearson Education, Inc. All Rights Reserved Glycocalyx (1 of 2) External to the cell wall Viscous and gelatinous Made of polysaccharide and/or polypeptide Two types – Capsule: neatly organized and firmly attached – Slime layer: unorganized and loose Copyright © 2019 Pearson Education, Inc. All Rights Reserved Glycocalyx (2 of 2) Contribute to virulence – Capsules prevent phagocytosis – Extracellular polymeric substance helps form biofilms Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 24-11 Streptococcus Pneumoniae, the Cause of Pneumococcal Pneumonia For Long description, see slide 152: Appendix 9 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Flagella (1 of 3) Filamentous appendages external of the cell Propel bacteria Made of protein flagellin Copyright © 2019 Pearson Education, Inc. All Rights Reserved Flagella (2 of 3) Three parts: – Filament: outermost region – Hook: attaches to the filament – Basal body: consists of rod and pairs of rings; anchors flagellum to the cell wall and membrane Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-8a The Structure of a Prokaryotic Flagellum For Long description, see slide 153: Appendix 10 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-8b The Structure of a Prokaryotic Flagellum For Long description, see slide 154: Appendix 11 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-7 Arrangements of Bacterial Flagella For Long description, see slide 155: Appendix 12 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Flagella (3 of 3) Flagella allow bacteria to move toward or away from stimuli (taxis) Flagella rotate to “run” or “tumble” Flagella proteins are H antigens and distinguish among serovars (e.g., Escherichia coli O157:H7) Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-9a Flagella and Bacterial Motility For Long description, see slide 156: Appendix 13 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-9b Flagella and Bacterial Motility For Long description, see slide 157: Appendix 14 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Archaella Archaeal motility structure Made of glycoproteins archaellins Anchored to the cell Archaella (singular: archlaellum) rotate like flagella Copyright © 2019 Pearson Education, Inc. All Rights Reserved Axial Filaments Also called endoflagella Found in spirochetes Anchored at one end of a cell Rotation causes cell to move like a corkscrew Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-10a Axial Filaments For Long description, see slide 158: Appendix 15 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-10b Axial Filaments For Long description, see slide 159: Appendix 16 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Fimbriae and Pili (1 of 2) Fimbriae – Hairlike appendages that allow for attachment Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-11 Fimbriae For Long description, see slide 160: Appendix 17 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Fimbriae and Pili (2 of 2) Pili – Involved in motility (gliding and twitching motility) – Conjugation pili involved in DNA transfer from one cell to another Copyright © 2019 Pearson Education, Inc. All Rights Reserved Check Your Understanding-3 Check Your Understanding 4-3 Why are bacterial capsules medically important 4-4 How do bacteria move? Copyright © 2019 Pearson Education, Inc. All Rights Reserved The Cell Wall (1 of 2) Learning Objectives 4-5 Compare and contrast the cell walls of gram-positive bacteria, gram-negative bacteria, acid-fast bacteria, archaea, and mycoplasmas. 4-6 Compare and contrast archaea and mycoplasmas. 4-7 Differentiate protoplast, spheroplast, and L form Copyright © 2019 Pearson Education, Inc. All Rights Reserved The Cell Wall (2 of 2) Prevents osmotic lysis and protects the cell membrane Made of peptidoglycan (in bacteria) Contributes to pathogenicity Copyright © 2019 Pearson Education, Inc. All Rights Reserved Foundation Figure 4-6 the Structure of a Prokaryotic Cell For Long description, see slide 161: Appendix 18 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Composition and Characteristics Peptidoglycan – Polymer of a repeating disaccharide in rows: ▪ N-acetylglucosamine(NAG) ▪ N-acetylmuramicacid (NAM) Rows are linked by polypeptides Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-12 For Long description, see slide 162: Appendix 19 N-Acetylglucosamine (NAG) and N-Acetylmuramic Acid (NAM) Joined as in a Peptidoglycan Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-13a Bacterial Cell Walls For Long description, see slide 163: Appendix 20 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Gram-Positive Cell Walls (1 of 3) Thick peptidoglycan Teichoic acids Copyright © 2019 Pearson Education, Inc. All Rights Reserved Gram-Negative Cell Walls (1 of 4) Thin peptidoglycan Outer membrane Periplasmic space Copyright © 2019 Pearson Education, Inc. All Rights Reserved Gram-Positive Cell Walls (2 of 3) Teichoic acids – Lipoteichoic acid links cell wall to plasma membrane – Wall teichoic acid links the peptidoglycan – Carry a negative charge – Regulate movement of cations Polysaccharides and teichoic acids provide antigenic specificity Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-13b Bacterial Cell Walls For Long description, see slide 164: Appendix 21 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Gram-Negative Cell Walls (2 of 4) Periplasm between the outer membrane and the plasma membrane contains peptidoglycan Outer membrane made of polysaccharides, lipoproteins, and phospholipids Copyright © 2019 Pearson Education, Inc. All Rights Reserved Gram-Negative Cell Walls (3 of 4) Protect from phagocytes, complement, and antibiotics Made of lipopolysaccharide (LPS) – O polysaccharide functions as antigen (e.g., E. coli O157:H7) – Lipid A is an endotoxin embedded in the top layer Porins (proteins) form channels through membrane Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-13c Bacterial Cell Walls For Long description, see slide 165: Appendix 22 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Cell Walls and the Gram Stain Mechanism Crystal violet-iodine crystals form inside cell Gram-positive – Alcohol dehydrates peptidoglycan – CV-I crystals do not leave Gram-negative – Alcohol dissolves outer membrane and leaves holes in peptidoglycan – CV-I washes out; cells are colorless – Safranin added to stain cells Copyright © 2019 Pearson Education, Inc. All Rights Reserved Table 4-1 Some Comparative Characteristics of Gram-Positive and Gram-Negative Bacteria For Long description, see slide 166: Appendix 23 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Gram-Positive Cell Walls (3 of 3) 2 rings in basal body of flagella Produce exotoxins High susceptibility to penicillin Disrupted by lysozyme Copyright © 2019 Pearson Education, Inc. All Rights Reserved Gram-Negative Cell Walls (4 of 4) 4 rings in basal body of flagella Produce endotoxins and exotoxins Low susceptibility to penicillin Copyright © 2019 Pearson Education, Inc. All Rights Reserved Atypical Cell Walls (1 of 2) Acid-fast cell walls – Like gram-positive cell walls – Waxy lipid (mycolic acid) bound to peptidoglycan – Mycobacterium – Nocardia – Stain with carbolfuchsin Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 24.7 Mycobacterium Tuberculosis For Long description, see slide 167: Appendix 24 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Atypical Cell Walls (2 of 2) Mycoplasmas – Lack cell walls – Sterols in plasma membrane Archaea – Wall-less, or – Walls of pseudomurein (lack NAM and D-aminoacids) Copyright © 2019 Pearson Education, Inc. All Rights Reserved Damage to the Cell Wall Lysozyme hydrolyzes bonds in peptidoglycan Penicillin inhibits peptide bridges in peptidoglycan Protoplast is a wall-less gram-positive cell Spheroplast is a wall-less gram-negative cell – Protoplasts and spheroplasts are susceptible to osmotic lysis L forms are wall-less cells that swell into irregular shapes Copyright © 2019 Pearson Education, Inc. All Rights Reserved Check Your Understanding-4 Check Your Understanding 4-5 Why are drugs that target cell wall synthesis useful? 4-6 Why are mycoplasmas resistant to antibiotics that interfere with cell wall synthesis? 4-7 How do protoplasts differ from L forms? Copyright © 2019 Pearson Education, Inc. All Rights Reserved Structures Internal to the Cell Wall Learning Objectives 4-8 Describe the structure, chemistry, and functions of the prokaryotic plasma membrane. 4-9 Define simple diffusion, facilitated diffusion, osmosis, active transport, and group translocation. 4-10 Identify the functions of the nucleoid and ribosomes. 4-11 Identify the functions of four inclusions. 4-12 Describe the functions of endospores, sporulation, and endospore germination Copyright © 2019 Pearson Education, Inc. All Rights Reserved The Plasma (Cytoplasmic) Membrane (1 of 4) Phospholipid bilayer that encloses the cytoplasm Peripheral proteins on the membrane surface Integral and transmembrane proteins penetrate the membrane Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-14a Plasma Membrane For Long description, see slide 168: Appendix 25 (a) A diagram and micrograph showing the lipid bilayer forming the inner plasma membrane of the gram-negative bacterium Vibrio cholerae Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-14b Plasma Membrane For Long description, see slide 169: Appendix 26 (b) A portion of the inner membrane showing the lipid bilayer and proteins Copyright © 2019 Pearson Education, Inc. All Rights Reserved Structure Fluid mosaic model – Membrane is as viscous as olive oil – Proteins move freely for various functions – Phospholipids rotate and move laterally – Self-sealing Copyright © 2019 Pearson Education, Inc. All Rights Reserved Functions (1 of 2) The plasma membrane’s selective permeability allows the passage of some molecules, but not others Contain enzymes for ATP production Some membranes have photosynthetic pigments on foldings called chromatophores Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-15 Chromatophores For Long description, see slide 170: Appendix 27 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Functions (2 of 2) Damage to the membrane by alcohols, quaternary ammonium (detergents), and polymyxin antibiotics causes leakage of cell contents Copyright © 2019 Pearson Education, Inc. All Rights Reserved The Movement of Materials across Membranes Passive processes: substances move from high concentration to low concentration; no energy expended Active processes: substances move from low concentration to high concentration; energy expended Copyright © 2019 Pearson Education, Inc. All Rights Reserved Passive Processes (1 of 5) Simple diffusion: movement of a solute from an area of high concentration to an area of low concentration Continue until molecules reach equilibrium Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-17a Passive Processes For Long description, see slide 171: Appendix 28 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Animation: Passive Transport: Principles of Diffusion Copyright © 2019 Pearson Education, Inc. All Rights Reserved Passive Processes (2 of 5) Facilitated diffusion: solute combines with a transporter protein in the membrane Transports ions and larger molecules across a membrane with the concentration gradient Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-17b-c Passive Processes For Long description, see slide 172: Appendix 29 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Animation: Passive Transport: Special Types of Diffusion Copyright © 2019 Pearson Education, Inc. All Rights Reserved Passive Processes (3 of 5) Osmosis: the movement of water across a selectively permeable membrane from an area of high water to an area of lower water concentration Through lipid layer Aquaporins (water channels) Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-17d Passive Processes For Long description, see slide 173: Appendix 30 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Passive Processes (4 of 5) Osmotic pressure: the pressure needed to stop the movement of water across the membrane Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-18a-b The Principle of Osmosis For Long description, see slide 174: Appendix 31 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Passive Processes (5 of 5) Isotonic solution: solute concentrations equal inside and outside of cell; water is at equilibrium Hypotonic solution: solute concentration is lower outside than inside the cell; water moves into cell Hypertonic solution: solute concentration is higher outside of cell than inside; water moves out of cell Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-18c-e The Principle of Osmosis For Long description, see slide 175: Appendix 32 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Active Processes Active transport: requires a transporter protein and AT P; goes against gradient Group translocation: requires a transporter protein and phosphoenolpyruvic acid (PEP); substance is altered as it crosses the membrane Copyright © 2019 Pearson Education, Inc. All Rights Reserved Check Your Understanding-5 Check Your Understanding 4-8 Which agents can cause injury to the bacterial plasma membrane? 4-9 How are simple diffusion and facilitated diffusion similar? How are they different? Copyright © 2019 Pearson Education, Inc. All Rights Reserved Cytoplasm (1 of 3) The substance inside the plasma membrane Eighty percent water plus proteins, carbohydrates, lipids, and ions Cytoskeleton Copyright © 2019 Pearson Education, Inc. All Rights Reserved The Nucleoid Bacterial chromosome: circular thread of DNA that contains the cell's genetic information Plasmids: extrachromosomal genetic elements; carry non-crucial genes (g., antibiotic resistance, production of toxins) ram Copyright © 2019 Pearson Education, Inc. All Rights Reserved Ribosomes (1 of 3) Sites of protein synthesis Made of protein and ribosomal RNA 70S – 50S + 30S subunits Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-19 The Prokaryotic Ribosome For Long description, see slide 176: Appendix 33 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Inclusions Metachromatic granules (volutin)-phosphate reserves Polysaccharide granules-energy reserves Lipid inclusions-energy reserves Sulfur granules-energy reserves Carboxysomes-RuBis CO enzyme for CO2 fixation during photosynthesis Gas vacuoles-protein-covered cylinders that maintain buoyancy Magnetosomes-iron oxide inclusions; destroy H2O2 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-20 Magnetosomes For Long description, see slide 177: Appendix 34 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Endospores Resting cells; produced when nutrients are depleted Resistant to desiccation, heat, chemicals, and radiation Produced by Bacillus and Clostridium Sporulation: endospore formation Germination: endospore returns to vegetative state Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-21b Formation of Endospores by Sporulation Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-21a Formation of Endospores by Sporulation For Long description, see slide 178: Appendix 35 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Check Your Understanding-6 Check Your Understanding 4-10 Where is the DNA located in a prokaryotic cell? 4-11 What is the general function of inclusions? 4-12 Under what conditions do endospores form? Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-22a Eukaryotic Cells Showing Typical Structures For Long description, see slide 179: Appendix 36 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-22b Eukaryotic Cells Showing Typical Structures For Long description, see slide 180: Appendix 37 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Flagella and Cilia (1 of 3) Learning Objective 4-13 Differentiate prokaryotic and eukaryotic flagella Copyright © 2019 Pearson Education, Inc. All Rights Reserved Flagella and Cilia (2 of 3) Projections used for locomotion or moving substances along the cell surface Flagella-long projections; few in number Cilia-short projections; numerous Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-23a-b Eukaryotic Flagella and Cilia For Long description, seae slide 181: Appendix 38 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Flagella and Cilia (3 of 3) Both consist of microtubules made of the protein tubulin Microtubules are organized as 9 pairs in a ring, plus 2 microtubules in the center (9 + 2 array) Allow flagella to move in a wavelike manner Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-23c Eukaryotic Flagella and Cilia For Long description, see slide 182: Appendix 39 Copyright © 2019 Pearson Education, Inc. All Rights Reserved The Cell Wall and Glycocalyx (1 of 2) Learning Objective 4-14 Compare and contrast prokaryotic and eukaryotic cell walls and glycocalyxes Copyright © 2019 Pearson Education, Inc. All Rights Reserved The Cell Wall and Glycocalyx (2 of 2) Cell wall – Found in plants, algae, and fungi – Made of carbohydrates (cellulose-plants, chitin- fungi, glucan and mannan-yeasts) Glycocalyx – Carbohydrates bonded to proteins and lipids in the plasma membrane – Found in animal cells Copyright © 2019 Pearson Education, Inc. All Rights Reserved The Plasma (Cytoplasmic) Membrane (2 of 4) Learning Objective 4-15 Compare and contrast prokaryotic and eukaryotic plasma membranes Copyright © 2019 Pearson Education, Inc. All Rights Reserved The Plasma (Cytoplasmic) Membrane (3 of 4) Similar in structure to prokaryotic cell membranes – Phospholipid bilayer – Integral and peripheral proteins Differences in structure – Sterols-complex lipids – Carbohydrates-for attachment and cell-to-cell recognition Copyright © 2019 Pearson Education, Inc. All Rights Reserved The Plasma (Cytoplasmic) Membrane (4 of 4) Similar in function to prokaryotic cell membranes – Selective permeability – Simple diffusion, facilitated diffusion, osmosis, active transport Differences in function – Endocytosis-phagocytosis and pinocytosis – Phagocytosis: pseudopods extend and engulf particles – Pinocytosis: membrane folds inward, bringing in fluid and dissolved substances Copyright © 2019 Pearson Education, Inc. All Rights Reserved Cytoplasm (2 of 3) Learning Objective 4-16 Compare and contrast prokaryotic and eukaryotic cytoplasms Copyright © 2019 Pearson Education, Inc. All Rights Reserved Cytoplasm (3 of 3) Cytoplasm: substance inside the plasma and outside the nucleus Cytosol: fluid portion of cytoplasm Cytoskeleton: made of microfilaments and intermediate filaments; gives shape and support Cytoplasmic streaming: movement of the cytoplasm throughout a cell Copyright © 2019 Pearson Education, Inc. All Rights Reserved Ribosomes (2 of 3) Learning Objective 4-17 Compare the structure and function of eukaryotic and prokaryotic ribosomes Copyright © 2019 Pearson Education, Inc. All Rights Reserved Ribosomes (3 of 3) Sites of protein synthesis 80S – Consists of the large 60S subunit and the small 40S subunit – Membrane-bound: attached to endoplasmic reticulum – Free: in cytoplasm 70S – In chloroplasts and mitochondria Copyright © 2019 Pearson Education, Inc. All Rights Reserved Check Your Understanding-7 Check Your Understanding 4-13 – 4-16 Identify at least one significant difference between eukaryotic and prokaryotic flagella and cilia, cell walls, plasma membranes, and cytoplasm. 4-17 The antibiotic erythromycin binds with the 50S portion of a ribosome. What effect does this have on a prokaryotic cell? On a eukaryotic cell? Copyright © 2019 Pearson Education, Inc. All Rights Reserved Organelles (1 of 3) Learning Objectives 4-18 Define organelle. 4-19 Describe the functions of the nucleus, endoplasmic reticulum, Golgi complex, lysosomes, vacuoles, mitochondria, chloroplasts, peroxisomes, and centrosomes Copyright © 2019 Pearson Education, Inc. All Rights Reserved The Nucleus Nucleus – Double membrane structure (nuclear envelope) that contains the cell’s DNA – DNA is complexed with histone proteins to form chromatin – During mitosis and meiosis, chromatin condenses into chromosomes Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-24 The Eukaryotic Nucleus For Long description, see slide 183: Appendix 40 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Endoplasmic Reticulum Folded transport network Rough ER: studded with ribosomes; sites of protein synthesis Smooth ER: no ribosomes; synthesizes cell membranes, fats, and hormones Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-25 Rough Endoplasmic Reticulum and Ribosomes For Long description, see slide 184: Appendix 41 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-25b Rough Endoplasmic Reticulum and Ribosomes For Long description, see slide 185: Appendix 42 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Golgi Complex Transport organelle Modifies proteins from the ER Transports modified proteins via secretory vesicles to the plasma membrane Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-26 Golgi Complex For Long description, see slide 186: Appendix 43 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Organelles (2 of 3) Lysosomes – Vesicles formed in the Golgi complex – Contain digestive enzymes Vacuoles – Cavities in the cell formed from the Golgi complex – Bring food into cells; provide shape and storage Copyright © 2019 Pearson Education, Inc. All Rights Reserved Mitochondria Double membrane Contain inner folds (cristae) and fluid (matrix) Involved in cellular respiration (ATP production) Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-27 Mitochondria For Long description, see slide 187: Appendix 44 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Chloroplasts Locations of photosynthesis Contain flattened membranes (thylakoids) that contain chlorophyll Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-28 Chloroplasts For Long description, see slide 188: Appendix 45 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 4-28b Chloroplasts For Long description, see slide 189: Appendix 46 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Organelles (3 of 3) Peroxisomes – Oxidize fatty acids; destroy H2O2 Centrosomes – Networks of protein fibers and centrioles – Form the mitotic spindle; critical role in cell division Copyright © 2019 Pearson Education, Inc. All Rights Reserved Check Your Understanding-8 Check Your Understanding 4-18 Compare the structure of the nucleus of a eukaryote and the nucleoid of a prokaryote. 4-19 How do rough and smooth ER compare structurally and functionally? Copyright © 2019 Pearson Education, Inc. All Rights Reserved The Evolution of Eukaryotes (1 of 3) Learning Objective 4-20 Discuss evidence that supports the endosymbiotic theory of eukaryotic evolution Copyright © 2019 Pearson Education, Inc. All Rights Reserved The Evolution of Eukaryotes (2 of 3) Life arose as simple organisms 3.5 to 4 billion years ago First eukaryotes evolved 2.5 billion years ago Copyright © 2019 Pearson Education, Inc. All Rights Reserved The Evolution of Eukaryotes (3 of 3) Endosymbiotic theory – Larger bacterial cells engulfed smaller bacterial cells, developing the first eukaryotes – Ingested photosynthetic bacteria became chloroplasts – Ingested aerobic bacteria became mitochondria Copyright © 2019 Pearson Education, Inc. All Rights Reserved Figure 10-2 A Model of the Origin of Eukaryotes For Long description, see slide 190: Appendix 47 Copyright © 2019 Pearson Education, Inc. All Rights Reserved Check Your Understanding-9 Check Your Understanding 4-20 Which three organelles are not associated with the Golgi complex? What does this suggest about their origin? Copyright © 2019 Pearson Education, Inc. All Rights Reserved Copyright This work is protected by United States copyright laws and is provided solely for the use of instructors in teaching their courses and assessing student learning. Dissemination or sale of any part of this work (including on the World Wide Web) will destroy the integrity of the work and is not permitted. The work and materials from it should never be made available to students except by instructors using the accompanying text in their classes. All recipients of this work are expected to abide by these restrictions and to honor the intended pedagogical purposes and the needs of other instructors who rely on these materials Copyright © 2019 Pearson Education, Inc. All Rights Reserved