Chapter 5 Microbiology-1 PDF

Chapter 5 A Survey of Eurkaryotic Cells and Microorganisms Lecture Outline See separate PowerPoint slides for all figures and tables pre-inserted into PowerPoint without notes. © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom...

Chapter 5 A Survey of Eurkaryotic Cells and Microorganisms Lecture Outline See separate PowerPoint slides for all figures and tables pre-inserted into PowerPoint without notes. © McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw-Hill Education.  The History of Eukaryotes They first appeared approximately 2 billion years ago Evidence suggests evolution from prokaryotic organisms by symbiosis Organelles originated from prokaryotic cells trapped inside them © Andrew H.Knoll 5-2 © McGraw-Hill Education. Evolution of Eukaryotic Organisms (Endosymbiotic Theory) 5-3 © McGraw-Hill Education.  Eukaryotic Microbes TABLE 5.1 Eukaryotic Organisms Studied in Microbiology May Be Unicellular, Unicellular, a Few Multicellular Except Reproductive Colonial, or Colonial Stages Multicellular Helminths (parasitic worms) Protozoa Fungi, Algae Arthropods (animals vectors of diseases) 5-4 © McGraw-Hill Education. The Eukaryotic Cell 5-5 © McGraw-Hill Education. Organization of the Eukaryotic Cell (1 of 3) Eukaryotic cell – External structures – Boundary of cell – Organelles and other components within the cell membrane External structures – Glycocalyx  Capsules  Slimes Boundary of cell – Cell wall – Cell/cytoplasmic membrane 5-6 © McGraw-Hill Education.  Organization of the Eukaryotic Cell (2 of 3) Organelles and other components within the cell membrane – Cytoplasmic matrix – Nucleus – Organelles – Locomotor organelles – Ribosomes – Cytoskeleton Nucleus – Nuclear envelope – Nucleolus – Chromosomes 5-7 © McGraw-Hill Education.  Organization of the Eukaryotic Cell (3 of 3) Organelles – Endoplasmic reticulum – Golgi complex Mitochondria – Mitochondria – Chloroplasts Locomotor organelles – Flagella – Cilia Cytoskeleton – Microtubules – Microfilaments 5-8 © McGraw-Hill Education.  External Structures: Locomotor Appendages (1 of 5) Flagella – Long, sheathed cylinder containing microtubules in a 9+2 arrangement – Covered by an extension of the cell membrane – 10× thicker than prokaryotic flagella 5-9 © McGraw-Hill Education. External Structures: Locomotor Appendages (2 of 5) Courtesy of Richard Allen Courtesy of Richard Allen 5-10 © McGraw-Hill Education.  External Structures: Locomotor Appendages (3 of 5) c) Whips back and forth and pushes in snakelike pattern 5-11 © McGraw-Hill Education.  External Structures: Locomotor Appendages (4 of 5) Cilia – Similar in overall structure to flagella, but shorter and more numerous – Found only on a single group of protozoa and certain animal cells – Function in motility, feeding, and filtering 5-12 © McGraw-Hill Education. External Structures: Locomotor Appendages (5 of 5) Nancy Nehring/Getty Images 5-13 © McGraw-Hill Education.  External Structures: Glycocalyx An outermost boundary that comes into direct contact with environment Usually composed of polysaccharides Appears as a network of fibers, a slime layer or a capsule Functions in adherence, protection, and signal reception Beneath the glycocalyx – Fungi and most algae have a thick, rigid cell wall – Protozoa, a few algae, and all animal cells lack a cell wall and have only a membrane 5-14 © McGraw-Hill Education.  Boundary of the Cell: Cell Wall Rigid, provides structural support and shape Fungi have thick inner layer of polysaccharide fibers composed of chitin or cellulose and a thin layer of mixed glycans Algae – varies in chemical composition; substances commonly found include cellulose, pectin, mannans, silicon dioxide, and calcium carbonate 5-15 © McGraw-Hill Education.  Boundary of the Cell: Cell/Cytoplasmic Membrane Typical bilayer of phospholipids and proteins Sterols confer stability Serves as selectively permeable barrier in transport Eukaryotic cells also contain membrane- bound organelles that account for 60-80% of their volume 5-16 © McGraw-Hill Education.  Concept Check: (1) Which part of the Eukaryotic cell is responsible for contacting the outside environment and signaling between cells? A. Flagella B. Cell Wall C. Glycocalyx D. Cell Membrane 5-17 © McGraw-Hill Education.  Concept Check: (2) Which part of the Eukaryotic cell is responsible for contacting the outside environment and signaling between cells? A. Flagella B. Cell Wall C. Glycocalyx D. Cell Membrane Answer: C 5-18 © McGraw-Hill Education.  Organelles and Other Internal Structures TABLE 5.3 Function of Internal Structures within the Eukaryotic Cell Nucleus Genetic center of the cell; repository of DNA; synthesis of RNA Nucleolus Ribosomal RNA synthesis; ribosome construction Endoplasmic reticulum Transport of material; lipid synthesis Golgi apparatus Packaging and modification of proteins prior to secretion Lysosomes Intracellular digestion Temporary storage and transport; digestion (food vacuoles); Vacuoles regulation of osmotic pressure (water vacuoles) Energy production using the Krebs cycle, electron transport, and Mitochondria oxidative phosphorylation Conversion of sunlight into chemical energy through Chloroplast photosynthesis Ribosomes Proteins synthesis Composed of microfilaments and microtubules; provides cell Cytoskeleton structure and movement; anchors organelles 5-19 © McGraw-Hill Education.  Organelles and Other Internal Structures: Nucleus (1 of 3) Compact sphere, most prominent organelle of eukaryotic cell Nuclear envelope composed of two parallel membranes separated by a narrow space and is perforated with pores Contains chromosomes Nucleolus – dark area for rRNA synthesis and ribosome assembly 5-20 © McGraw-Hill Education. Organelles and Other Internal Structures: Nucleus (2 of 3) © Don W. Fawcett/Science Source 5-21 © McGraw-Hill Education. Organelles and Other Internal Structures: Nucleus (3 of 3) 5-22 © McGraw-Hill Education. Nuclear Changes During Mitosis 5-23 © McGraw-Hill Education.  Internal Structures: Endoplasmic Reticulum Two types: – Rough endoplasmic reticulum (RER) – originates from the outer membrane of the nuclear envelope and extends in a continuous network through cytoplasm; rough due to ribosomes; proteins synthesized and shunted into the ER for packaging and transport; first step in secretory pathway – Smooth endoplasmic reticulum (SER) – closed tubular network without ribosomes; functions in nutrient processing, synthesis, and storage of lipids 5-24 © McGraw-Hill Education. Rough Endoplasmic Reticulum 5-25 © McGraw-Hill Education. Internal Structures: Golgi Apparatus (1 of 2) Modifies, stores, and packages proteins Consists of a stack of flattened sacs called cisternae 5-26 © McGraw-Hill Education. Internal Structures: Golgi Apparatus (2 of 2) 5-27 © McGraw-Hill Education.  Synthesis and Transport Machine (1 of 4) Nucleus RER Golgi vesicles secretion The nucleolus provides ribosomes that travel to the RER Transport vesicles from the ER containing proteins go to the Golgi apparatus for modification and maturation Condensing vesicles transport proteins to organelles or into secretory vesicles to be exported outside 5-28 © McGraw-Hill Education. Synthesis and Transport Machine (2 of 4) 5-29 © McGraw-Hill Education.  Synthesis and Transport Machine (3 of 4) Lysosomes Vesicles containing enzymes that originate from Golgi apparatus – Involved in intracellular digestion of food particles and in protection against invading microbes Vacuoles Membrane bound sacs containing particles to be digested, excreted, or stored Phagosomes Vacuoles merged with a lysosome 5-30 © McGraw-Hill Education. Synthesis and Transport Machine (4 of 4) 5-31 © McGraw-Hill Education.  Internal Structures: Mitochondria (1 of 2) Function in energy production and storage (ATP) Spherical organelle with an outer membrane and an inner membrane with folds called cristae Cristae membranes hold the enzymes and electron carriers of aerobic respiration Divide independently of cell DNA and prokaryotic ribosomes are contained in the spaces around the cristae called matrix 5-32 © McGraw-Hill Education. Internal Structures: Mitochondria (2 of 2) © Keith R. Porter/Science Source 5-33 © McGraw-Hill Education.  Internal Structures: Chloroplasts (1 of 2) Convert the energy of sunlight into chemical energy through photosynthesis Found in algae and plant cells Outer membrane covers inner membrane folded into sacs called thylakoids, stacked into grana. They carry pigments (chlorophyll and others) Primary producers of organic nutrients for other organisms 5-34 © McGraw-Hill Education. Internal Structures: Chloroplasts (2 of 2) 5-35 © McGraw-Hill Education.  Internal Structures: Ribosomes (1 of 2) Composed of rRNA and proteins Scattered in cytoplasm or associated with RER Larger than prokaryotic ribosomes Function in protein synthesis 5-36 © McGraw-Hill Education. Internal Structures: Ribosomes (2 of 2) 5-37 © McGraw-Hill Education. Internal Structures: The Cytoskeleton (1 of 2) Flexible framework of proteins, microfilaments and microtubules form network throughout cytoplasm Involved in organelles anchoring, movement of cytoplasm, amoeboid motion, transport, and structural support 5-38 © McGraw-Hill Education. Internal Structures: The Cytoskeleton (2 of 2) Alex Ritter, Jennifer Lippincott Schwartz, Gillian Griffiths/National Institutes of Health 5-39 © McGraw-Hill Education.  Comparing Prokaryotes, Eukaryotes & Viruses (1 of 3) TABLE 5.4 A General Comparison of Prokaryotic and Eukaryotic Cells and Viruses Prokaryotic Eukaryotic Function or Structure Characteristic* Viruses ** Cells Cells Genetics Nucleic acids + + + True nucleus - + - Nuclear envelope - + - Nucleoid + - - Reproduction Mitosis - + - Production of sex cells +/- + - Binary fission + + - Biosynthesis Independent + + - Golgi apparatus - + - Endoplasmic reticulum - + - Ribosomes +*** + - 5-40 © McGraw-Hill Education. Comparing Prokaryotes, Eukaryotes & Viruses (2 of 3) The figure of “TABLE 5.4” continues on this slide. Prokaryotic Eukaryotic Function or Structure Characteristic* Viruses ** Cells Cells Respiration Enzymes + + - Mitochondria - + - Photosynthesis Pigments +/- +/- - Chloroplasts - +/- - Motility/locomotor structures Flagella +/-*** +/- - Cilia - +/- - Shape/protection Cell membrane + + - - (have Cell wall +/-*** +/- capsids instead Capsule +/- +/- - 0.5-3 Size (in general) 2-100 µm