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Bell Ringer • Complete bell ringer on “Think-PairShare” worksheet silently • Advertisements tell you that bacteria and viruses are all over your home and that you need to buy antibacterial cleaning products. Should you? Suspended Curriculum Objectives • By the end of the lesson, students will be able to – 1) Describe the general properties and characteristics of bacteria, fungi, parasites, and viruses. – The will be demonstrated by the completion of a concept map as an exit slip Chapter 1 A Brief History of Microbiology © 2012 Pearson Education Inc. Lecture prepared by Mindy Miller-Kittrell North Carolina State University Microbiology • Microorganisms (microbes) – Tiny living things – too small to see with naked eye • Many are associated with disease – Pathogens • Roles of microbes in heath of living organisms and environment – Photosynthesis – Recycle nutrients and make nutrients in human body – Protect against diseases © 2012 Pearson Education Inc. The Early Years of Microbiology • What Does Life Really Look Like? – Antoni Van Leeuwenhoek (Dutch) – Began making and using simple microscopes – new microscopes 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 © 2012 Pearson Education Inc. Figure 1.2 Reproduction of Leeuwenhoek’s microscope Lens Specimen holder The Early Years of Microbiology • How Can Microbes Be Classified? – Linnaeus developed taxonomic system for grouping similar organisms together – Leeuwenhoek’s microorganisms grouped into six categories: – Bacteria – Archaea – Fungi – Protozoa – Algae – Small multicellular animals © 2012 Pearson Education Inc. The Early Years of Microbiology • Bacteria – Unicellular and lack nuclei (prokaryotes) – Much smaller than eukaryotes – Reproduce asexually – Binary fission – Cell walls contain peptidoglycan – Come in a variety of shapes – Coccus (spherical) – Bacillus (rodlike) – Spiral (corkscrew or curved) © 2012 Pearson Education Inc. Figure 1.4 Cells of the bacterium Streptococcus Nucleus of Prokaryotic bacterial cells eukaryotic cheek cell The Early Years of Microbiology • Archaea – – – – Unicellular and lack nuclei Much smaller than eukaryotes Reproduce asexually Cell walls composed of polymers other than peptidoglycan – Found in extreme conditions – Methanogens – Halophiles – Thermophiles © 2012 Pearson Education Inc. The Early Years of Microbiology • Fungi – Eukaryotic (have membrane-bound nucleus) – Obtain food from absorbing nutrients from environment – Cell walls made of chitin – Include – Molds – multicellular; grow as long filaments; reproduce by sexual and asexual spores – Yeasts – unicellular; reproduce by budding or sexual spores © 2012 Pearson Education Inc. Figure 1.5 Fungi-overview The Early Years of Microbiology • Protozoa – Single-celled eukaryotes – Similar to animals in nutrient needs and cellular structure – Live freely in water; some live in animal hosts (parasites) – Asexual (most) and sexual reproduction – Most are capable of movement by – Pseudopodia – Cilia – Flagella © 2012 Pearson Education Inc. Figure 1.6 Locomotive structures of protozoa-overview The Early Years of Microbiology • Algae – – – – Unicellular or multicellular Photosynthetic Sexual and asexual reproduction Categorized on the basis of pigmentation, storage products, and composition of cell wall – Chemicals from their cell walls are used to make microbiology lab media © 2012 Pearson Education Inc. Figure 1.7 Algae-overview Other Important Microorganisms • Parasitic worms – Helminths – Flatworms and roundworms – Eukaryotes – Microscopic to 7 meters long – Many cause disease – Eggs can be found in blood, feces, urine, lymph © 2012 Pearson Education Inc. Figure 1.8 An immature stage of a parasitic worm in blood Red blood cell Other Important Microorganisms • Viruses – Acellular – Tiny, cannot be seen with light microscopes – Obligate intracellular parasites – Can only reproduce by controlling the cellular machinery of other organisms – Contain a core of nucleic acid surrounded by a protein coat © 2012 Pearson Education Inc. Figure 1.9 Viruses infecting a bacterium Virus Bacterium Viruses assembling inside cell Cold Calling • State one role of microorganisms in humans or the environment • What microorganism is not composed of cells? • Name one prokaryotic microbe. • Which unicellular microbes lack a cell wall, but have a nucleus? Exit Slip • Concept Map