Chapter 1

• • Began making and using simple microscopes • Often made a new microscope for each specimen

  Antoni van Leeuwenhoek
• Examined water and visualized tiny animals, fungi, algae,

  and single-celled protozoa

  Animacules
• developed taxonomic system for naming plants and animals and grouping similar organisms together

  Carolus Linnaeus
• Leeuwenhoek's microorganisms are now grouped into six categories:

  • Bacteria • Archaea • Fungi • Protozoa • Algae • Small multicellular animals
• • Prokaryotic (lack nuclei) • Much smaller than eukaryotes • Found everywhere there is sufficient moisture; some have been isolated from extreme environments • Reproduce asexually

  Bacteria and Archaea
• Bacterial cell walls contain

  Peptidoglycan
• • Eukaryotic (have membrane-bound nucleus) • Obtain food from other organisms • Possess cell walls

  Fungi
• multicellular; grow as long filaments;

  reproduce by sexual and asexual spores

  Molds
• unicellular; reproduce asexually by budding;

  some produce sexual spores

  yeast
• Single-celled eukaryotes • Similar to animals in nutrient needs and cellular structure • Live freely in water; some live in animal hosts • Asexual (most) and sexual reproduction

  Protozoa
• cell extensions that flow in direction of

  travel

  Pseudopods
• numerous short protrusions that propel organisms through environment

  Cillia
• extensions of a cell that are fewer, longer, and more whiplike than cilia

  Flagella
• • Unicellular or multicellular • Photosynthetic • Simple reproductive structures • Categorized on the basis of pigmentation and composition of cell wall • Scientists and manufacturers use many algae-derived products

  Algae
• Some philosophers and scientists of the past thought living things arose from three processes:

  • Asexual reproduction • Sexual reproduction • Nonliving matter
• proposed spontaneous generation


  Aristotle
• • 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

  Redi's experiment
• • Scientists did not believe that animals could arise spontaneously, but that microbes could • experiments with beef gravy and infusions of plant material reinforced this idea

  Needham's experiments
• Results contradicted Needham's findings • Concluded that • Needham failed to heat vials sufficiently to kill all microbes or had not sealed vials tightly enough • Microorganisms exist in air and can contaminate experiments • Spontaneous generation of microorganisms does not occur

  Spallazani's experiment
• Scientists who debunked spontaneous generation

  Redi, Spallazani, Louis Pasteur
• Scientists who believe in spontaneous generation

  Aristotle and Needham (believes animals cannot rise from other organisms, but microbes can)
• • Performed investigations of spontaneous generation • When the "swan-necked" 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

  Pasteur's experiments
• Process of heating liquids just enough to kill most bacteria

  Pasteurization
• • Demonstrated fermentation does not require living cells • Showed enzymes promote chemical reactions • Began the field of biochemistry

  Buchner's experiment
• developed germ theory of disease

  Pasteur
• studied disease causation (etiology)

  Robert Koch
• • Simple staining techniques • First photomicrograph of bacteria • First photomicrograph of bacteria in diseased tissue • Techniques for estimating CFU/ml • Use of steam to sterilize media • Use of Petri dishes • Techniques to transfer bacteria • Bacteria as distinct species

  Robert Koch
• required medical students to wash their hands in chlorinated lime water • Resulted in higher patient survival rates

  Ignaz Semmelweis
• advanced antisepsis in health care settings • Sprayed wounds, surgical incisions, and dressings with carbolic acid (phenol)

  Joseph Lister
• the chemical reactions that occur in living organisms

  Metabolism
• The study of the body's defenses against specific pathogens


  Immunology
• The study of blood serum • Von Behring and Kitasato – presence in the blood of chemicals and cells that fight infection

  Serology