Fluent Essays

i can take it anytime from today- may 24 (but the earlier the better for me)- bidder who is good in microbiologypart 1 M/C and T/F (60 minutes)part 2 short questions (45minutes for 4 questions)(I have more notes/files for the 3 chapters but theyre too long now) chp_1_slides.pdf bio_243_ch3_slides.pdf chp_1_slides.pdf bio_243_ch3_slides.pdf bio_243_ch4_slides.pdf Unformatted Attachment Preview PowerPoint® Lecture Presentations prepared by Mindy Miller-Kittrell, North Carolina State University CHAPTER 1 A Brief History of Microbiology © 2018 Pearson Education, Inc. Figure 1.1 Antoni van Leeuwenhoek. © 2018 Pearson Education, Inc. Figure 1.3 The microbial world. The Early Years of Microbiology • What Does Life Really Look Like? • Antoni van Leeuwenhoek • Began making and using simple microscopes • Often made a new microscope for each specimen • Examined water and visualized tiny animals, fungi, algae, and single-celled protozoa; “animalcules” • By end of 19th century, these organisms were called microorganisms. © 2018 Pearson Education, Inc. Figure 1.2 Reproduction of Leeuwenhoek’s microscope. © 2018 Pearson Education, Inc. The Early Years of Microbiology • How Can Microbes Be Classified? • Carolus Linnaeus developed a taxonomic system for naming plants and animals and grouping similar organisms together. • Leeuwenhoek’s microorganisms can be grouped into six categories: • • • • • • © 2018 Pearson Education, Inc. Bacteria Archaea Fungi Protozoa Algae Small multicellular animals © 2018 Pearson Education, Inc. The Early Years of Microbiology Figure 1.4 Cells of the bacterium Streptococcus (dark blue) and two human cheek cells. • How Can Microbes Be Classified? • Bacteria and Archaea • Unicellular and lack nuclei • Much smaller than eukaryotes • Found everywhere there is sufficient moisture; some isolated in extreme environments • Reproduce asexually • Bacterial cell walls contain peptidoglycan, though some lack cell walls. • Archaeal cell walls are composed of polymers rather than peptidoglycan. © 2018 Pearson Education, Inc. © 2018 Pearson Education, Inc. The Early Years of Microbiology Figure 1.5 Fungi. • How Can Microbes Be Classified? • Fungi • • • • Eukaryotic (have membrane-bound nucleus) Obtain food from other organisms Possess cell walls Include: • Molds—multicellular; grow as long filaments; reproduce by sexual and asexual spores • Yeasts—unicellular; reproduce asexually by budding; some produce sexual spores © 2018 Pearson Education, Inc. © 2018 Pearson Education, Inc. The Early Years of Microbiology Figure 1.6 Locomotive structures of protozoa. • How Can Microbes Be Classified? • Protozoa • Single-celled eukaryotes • Similar to animals in nutrient needs and cellular structure • Live freely in water; some live in animal hosts • Asexual (mostly) and sexual reproduction • Most are capable of locomotion by: • Pseudopods—cell extensions that flow in direction of travel • Cilia—numerous short protrusions that propel organisms through its environment • Flagella—extensions of a cell that are fewer, longer, and more whiplike than cilia © 2018 Pearson Education, Inc. © 2018 Pearson Education, Inc. The Early Years of Microbiology Figure 1.7 Algae. • How Can Microbes Be Classified? • Algae • • • • Unicellular or multicellular Photosynthetic Simple reproductive structures Categorized on the basis of pigmentation and composition of cell wall © 2018 Pearson Education, Inc. The Early Years of Microbiology © 2018 Pearson Education, Inc. Figure 1.8 An immature stage of a parasitic worm in blood. • How Can Microbes Be Classified? • Other organisms of importance to microbiologists • Parasites • Viruses © 2018 Pearson Education, Inc. Figure 1.9 A colorized electron microscope image of viruses infecting a bacterium. © 2018 Pearson Education, Inc. The Early Years of Microbiology • Tell Me Why • Some people consider Leeuwenhoek the “Father of Microbiology.” Explain why this moniker makes sense. © 2018 Pearson Education, Inc. © 2018 Pearson Education, Inc. The Golden Age of Microbiology The Golden Age of Microbiology • Scientists searched for answers to four questions: • Does Microbial Life Spontaneously Generate? • • • • Is spontaneous generation of microbial life possible? What causes fermentation? What causes disease? How can we prevent infection and disease? • Some philosophers and scientists of the past thought living things arose from three processes: • Asexual reproduction • Sexual reproduction • Nonliving matter • Aristotle proposed spontaneous generation. • Living things can arise from nonliving matter. © 2018 Pearson Education, Inc. The Golden Age of Microbiology © 2018 Pearson Education, Inc. Figure 1.10 Redi’s experiments. • Does Microbial Life Spontaneously Generate? • Redi’s experiments • When decaying meat was kept isolated from flies, maggots never developed. • Meat exposed to flies was soon infested. • As a result, scientists began to doubt Aristotle’s theory. © 2018 Pearson Education, Inc. © 2018 Pearson Education, Inc. The Golden Age of Microbiology The Golden Age of Microbiology • Does Microbial Life Spontaneously Generate? • Does Microbial Life Spontaneously Generate? • Needham’s experiments • Scientists agreed that large animals could not arise spontaneously, but believed microbes could. • Needham’s experiments with beef gravy and infusions of plant material reinforced this idea. • Spallanzani’s experiments • His experiments contradicted Needham’s findings. • Concluded that: • Needham failed to heat vials sufficiently to kill all microbes or had not sealed them tightly enough. • Microorganisms exist in air and can contaminate experiments. • Spontaneous generation of microorganisms does not occur; all living things arise from other living things. • Critics said sealed vials did not allow enough air for organisms to survive and that prolonged heating destroyed the “life force.” © 2018 Pearson Education, Inc. © 2018 Pearson Education, Inc. Figure 1.11 Louis Pasteur. The Golden Age of Microbiology • Does Microbial Life Spontaneously Generate? • Pasteur’s experiments • Performed experiments with “swan-necked” flasks • When the flasks remained upright, no microbial growth appeared. • When the flask was tilted, dust from the bend in the neck seeped back into the flask and made the infusion cloudy with microbes within a day. © 2018 Pearson Education, Inc. Figure 1.12 Pasteur’s experiments with “swan-necked flasks.” © 2018 Pearson Education, Inc. The Golden Age of Microbiology • Does Microbial Life Spontaneously Generate? • The scientific method • Debate over spontaneous generation led in part to development of scientific method. • Observation leads to question • Question generates hypothesis • Hypothesis is tested through experiment(s) • Results prove or disprove hypothesis • Accepted hypothesis leads to theory/law • Disproved hypothesis is rejected or modified © 2018 Pearson Education, Inc. Figure 1.13 The scientific method, which forms a framework for scientific research. © 2018 Pearson Education, Inc. The Golden Age of Microbiology • Dr. Bauman’s Microbiology Video Tutor • For more information, listen to Dr. Bauman describe the steps of the scientific method and discuss several examples. © 2018 Pearson Education, Inc. © 2018 Pearson Education, Inc. The Golden Age of Microbiology The Golden Age of Microbiology • What Causes Fermentation? • What Causes Fermentation? • Spoiled wine threatened livelihood of many grape growers. • Wine makers funded research of methods to promote production of alcohol and prevent spoilage during fermentation. • The debate over the cause of fermentation reactions was also linked to the debate over spontaneous generation. © 2018 Pearson Education, Inc. Figure 1.14 How Pasteur applied the scientific method in investigating the nature of fermentation. • Pasteur’s experiments • Some scientists believed air caused fermentation; others insisted that living organisms caused fermentation. • Pasteur conducted a series of experiments that addressed the cause of fermentation. © 2018 Pearson Education, Inc. The Golden Age of Microbiology • What Causes Fermentation? • Pasteur’s experiments • Led to the development of pasteurization • Process of heating liquids just enough to kill most bacteria • Began the field of industrial microbiology • Intentional use of microbes for manufacturing products © 2018 Pearson Education, Inc. Table 1.1 Some Industrial Uses of Microbes © 2018 Pearson Education, Inc. The Golden Age of Microbiology • What Causes Fermentation? • Buchner’s experiments • Demonstrated fermentation does not require living cells • Showed enzymes promote chemical reactions • Buchner’s work began the field of biochemistry. © 2018 Pearson Education, Inc. © 2018 Pearson Education, Inc. The Golden Age of Microbiology Figure 1.15 Robert Koch. • What Causes Disease? • Pasteur developed the germ theory of disease. • Some diseases caused by specific germs called pathogens © 2018 Pearson Education, Inc. © 2018 Pearson Education, Inc. The Golden Age of Microbiology The Golden Age of Microbiology • What Causes Disease? • What Causes Disease? • Koch’s experiments • Robert Koch studied causative agents of disease (etiology). • Demonstrated a bacterium causes anthrax • Examined colonies of microorganisms © 2018 Pearson Education, Inc. Figure 1.16 Bacterial colonies on a solid surface (agar). • Koch’s experiments • • • • • • • • Simple staining techniques First photomicrograph of bacteria First photograph of bacteria in diseased tissue Techniques for estimating bacterial number in a solution Use of steam to sterilize growth media Use of Petri dishes Laboratory techniques to transfer bacteria Bacteria as distinct species © 2018 Pearson Education, Inc. The Golden Age of Microbiology • What Causes Disease? • Koch’s postulates • Suspected causative agent must be found in every case of the disease and be absent from healthy hosts. • Agent must be isolated and grown outside the host. • When agent is introduced to a healthy, susceptible host, the host must get the disease. • Same agent must be found in the diseased experimental host. © 2018 Pearson Education, Inc. © 2018 Pearson Education, Inc. Table 1.2 Other Notable Scientists of the “Golden Age of Microbiology” and the Agents of Disease They Discovered The Golden Age of Microbiology • What Causes Disease? • Gram’s stain • The most widely used staining technique • One of the first steps to identify a bacterium © 2018 Pearson Education, Inc. Figure 1.17 Results of Gram staining. © 2018 Pearson Education, Inc. The Golden Age of Microbiology • How Can We Prevent Infection and Disease? • • • • • • © 2018 Pearson Education, Inc. Figure 1.18 Florence Nightingale. © 2018 Pearson Education, Inc. Semmelweis and handwashing Lister’s antiseptic technique Nightingale and nursing Snow—infection control and epidemiology Jenner’s vaccine—field of immunology Ehrlich’s “magic bullets”—field of chemotherapy © 2018 Pearson Education, Inc. Figure 1.19 Some of the many scientific disciplines and applications that arose from the pioneering work of scientists just before and around the time of the Golden Age of Microbiology. © 2018 Pearson Education, Inc. The Golden Age of Microbiology Table 1.3 Fields of Microbiology (1 of 2) • Tell Me Why • Some people consider Pasteur or Koch to be the Father of Microbiology, rather than Leeuwenhoek. Why might they be correct? © 2018 Pearson Education, Inc. Table 1.3 Fields of Microbiology (2 of 2) © 2018 Pearson Education, Inc. The Modern Age of Microbiology • What Are the Basic Chemical Reactions of Life? • Biochemistry • Began with Pasteur’s work on fermentation and Buchner’s discovery of enzymes in yeast extract • Kluyver and van Niel—microbes used as model systems for biochemical reactions • Practical applications: • Design of herbicides and pesticides • Diagnosis of illnesses and monitoring of patients’ responses to treatment • Treatment of metabolic diseases • Drug design © 2018 Pearson Education, Inc. © 2018 Pearson Education, Inc. The Modern Age of Microbiology The Modern Age of Microbiology • How Do Genes Work? • How Do Genes Work? • • • • Microbial genetics Molecular biology Recombinant DNA technology Gene therapy © 2018 Pearson Education, Inc. • Microbial genetics • Avery, MacLeod, and McCarty determined genes are contained in molecules of DNA. • Beadle and Tatum established that a gene’s activity is related to protein function. • Translation of genetic information into protein explained • Rates and mechanisms of genetic mutation investigated • Identify methods cells use to control genetic expression © 2018 Pearson Education, Inc. The Modern Age of Microbiology The Modern Age of Microbiology • How Do Genes Work? • How Do Genes Work? • Molecular biology • Explanation of cell function at the molecular level • Pauling proposed that gene sequences could: • Provide understanding of evolutionary relationships and processes • Establish taxonomic categories to reflect these relationships • Identify existence of microbes that have never been cultured • Woese and Fox determined cells can be categorized as bacteria, archaea, or eukaryotes. • Cat scratch disease caused by unculturable organism © 2018 Pearson Education, Inc. • Recombinant DNA technology • Genes in microbes, plants, and animals manipulated for practical applications • Production of human blood-clotting factor by E. coli to aid hemophiliacs • Gene therapy • Inserting a missing gene or repairing a defective one in humans by inserting desired gene into host cells © 2018 Pearson Education, Inc. The Modern Age of Microbiology The Modern Age of Microbiology • What Role Do Microorganisms Play in the Environment? • How Do We Defend Against Disease? • Bioremediation uses living bacteria, fungi, and algae to detoxify polluted environments. • Recycling of chemicals such as carbon, nitrogen, and sulfur • Causation of disease • Serology • The study of blood serum • Von Behring and Kitasato—existence in the blood of chemicals and cells that fight infection • Immunology • The study of the body’s defenses against specific pathogens • Chemotherapy • Fleming discovered penicillin. • Domagk discovered sulfa drugs. © 2018 Pearson Education, Inc. Figure 1.20 The effects of penicillin on a bacterial “lawn” in a Petri dish. © 2018 Pearson Education, Inc. The Modern Age of Microbiology • What Will the Future Hold? • Microbiology is built on asking and answering questions. • The more questions we answer, the more questions we have. © 2018 Pearson Education, Inc. © 2018 Pearson Education, Inc. The Modern Age of Microbiology • Tell Me Why • Why are so many modern questions in microbiology related to genetics? © 2018 Pearson Education, Inc. PowerPoint® Lecture Presentations prepared by Mindy Miller-Kittrell, North Carolina State University CHAPTER 3 Cell Structure and Function © 2018 Pearson Education, Inc. Processes of Life • • • • Growth Reproduction Responsiveness Metabolism © 2018 Pearson Education, Inc. Table 3.1 Characteristics of Life and Their Distribution in Microbes © 2018 Pearson Education, Inc. Processes of Life • Tell Me Why • The smallest free-living microbe—the bacterium Mycoplasma—is nonmotile. Why is it alive, even though it cannot move? © 2018 Pearson Education, Inc. Figure 3.1 Examples of types of cells. © 2018 Pearson Education, Inc. Prokaryotic and Eukaryotic Cells: An Overview • Prokaryotes • Lack nucleus • Can read DNA and make protein simultaneously • Lack various internal structures bound with phospholipid membranes • Are typically 1.0 µm in diameter or smaller • Composed of bacteria and archaea © 2018 Pearson Education, Inc. Figure 3.2 Typical prokaryotic cell. © 2018 Pearson Education, Inc. Prokaryotic and Eukaryotic Cells: An Overview • Eukaryotes • • • • • Have nucleus Have internal membrane-bound organelles Are larger: 10–100 µm in diameter Have more complex structure Composed of algae, protozoa, fungi, animals, and plants © 2018 Pearson Education, Inc. Figure 3.3 Typical eukaryotic cell. © 2018 Pearson Education, Inc. Figure 3.4 Approximate size of various types of cells. © 2018 Pearson Education, Inc. Prokaryotic and Eukaryotic Cells: An Overview • Tell Me Why • In 1985, an Israeli scientist discovered the single-celled microbe Epulopiscium fishelsoni. This organism is visible with the naked eye. Why did the scientist initially think Epulopiscium was eukaryotic? • What discovery revealed that the microbe is really a giant bacterium? © 2018 Pearson Education, Inc. External Structures of Bacterial Cells • Glycocalyces • Gelatinous, sticky substance surrounding the outside of the cell • Composed of polysaccharides, polypeptides, or both © 2018 Pearson Education, Inc. External Structures of Bacterial Cells • Two Types of Glycocalyces • Capsule • Composed of organized repeating units of organic chemicals • Firmly attached to cell surface • May prevent bacteria from being recognized by host • Slime layer • Loosely attached to cell surface • Water-soluble • Sticky layer allows prokaryotes to attach to surfaces. © 2018 Pearson Education, Inc. Figure 3.5 Glycocalyces. © 2018 Pearson Education, Inc. Motility © 2018 Pearson Education, Inc. External Structures of Bacterial Cells • Flagella • Are responsible for movement • Have long structures that extend beyond cell surface • Are not present on all bacteria © 2018 Pearson Education, Inc. External Structures of Bacterial Cells • Flagella • Structure • Composed of filament, hook, and basal body • Basal body anchors the filament and hook to cell wall. © 2018 Pearson Education, Inc. Flagella: Structure © 2018 Pearson Education, Inc. Figure 3.6 Proximal structure of bacterial flagella. © 2018 Pearson Education, Inc. Figure 3.7 Micrographs of basic arrangements of bacterial flagella. © 2018 Pearson Education, Inc. Flagella: Arrangement © 2018 Pearson Education, Inc. Figure 3.8 Axial filament. © 2018 Pearson Education, Inc. Spirochetes © 2018 Pearson Education, Inc. External Structures of Bacterial Cells • Flagella • Function • Rotation propels bacterium through environment. • Rotation is reversible; can be counterclockwise or clockwise • Bacteria move in response to stimuli (taxis). • Runs • Tumbles © 2018 Pearson Education, Inc. Figure 3.9 Motion of a peritrichous bacterium. © 2018 Pearson Education, Inc. Flagella: Movement © 2018 Pearson Education, Inc. External Structures of Bacterial Cells • Fimbriae and Pili • Fimbriae • Sticky, bristlelike projections • Used by bacteria to adhere to one another and to substances in environment • Shorter than flagella • Serve an important function in biofilms © 2018 Pearson Education, Inc. Figure 3.10 Fimbriae. © 2018 Pearson Education, Inc. Figure 3.11 Biofilms. © 2018 Pearson Education, Inc. External Structures of Prokaryotic Cells • Fimbriae and Pili • Pili • • • • • Special type of fimbriae Also known as conjugation pili Longer than fimbriae but shorter than flagella Bacteria typically have only one or two per cell. Transfer DNA from one cell to another (conjugation) © 2018 Pearson Education, Inc. Figure 3.12 Pili. © 2018 Pearson Education, Inc. External Structures of Bacterial Cells • Tell Me Why • Why is a pilus a type of fimbria, but a flagellum is not a type of fimbria? © 2018 Pearson Education, Inc. Bacterial Cell Walls • Provide structure and shape and protect cell from ... Purchase answer to see full attachment