Microbiology Chapter 1 Flashcards

Microorganisms and Their Classification

• Leeuwenhoek was the first to examine microorganisms.
• Initial microorganisms included fungi, algae, and protozoa.
• Linnaeus developed the taxonomic system used for classifying organisms.
• Taxonomic hierarchy consists of kingdom, phylum, class, order, family, genus, and species.

Prokaryotes

• Types of prokaryotes: bacteria and archaea.
• Prokaryotes are smaller than eukaryotes.
• Bacteria and archaea thrive in moist environments, with some species being extremophiles.
• Reproduction in prokaryotes occurs asexually.
• Prokaryotic cell walls are mainly composed of peptidoglycan, although some bacteria lack cell walls.
• Archaea cell walls are made of polymers other than peptidoglycan.

Eukaryotes

• Eukaryotes include fungi, protozoa, and algae.
• Fungi have membrane-bound nuclei and obtain nutrients from other organisms.
• Two main types of fungi are molds (multicellular) and yeasts (unicellular).

Protozoa

• Protozoa are unicellular and similar to animals regarding nutrient needs and cellular structure.
• They can live freely in water or within hosts.
• Protozoa are capable of locomotion using structures such as pseudopods, cilia, and flagella.

Algae

• Algae can be unicellular or multicellular.
• Energy for algae is obtained through photosynthesis.

Viruses and Microbial Theories

• Viruses require an electron microscope for visualization.
• Aristotle proposed the spontaneous generation theory.
• Redi disproved spontaneous generation through experiments with exposed and isolated meat.
• Needham's experiments suggested microbes could spontaneously generate, which was later challenged by Spallanzini, who identified flaws in Needham's methods.
• Pasteur confirmed Spallanzini's conclusions with a swan-neck flask experiment that allowed air but not microbes to enter.

Scientific Contributions

• Steps of the scientific method: observe, question, formulate a hypothesis, conduct experiments, and analyze results.
• Pasteur is referred to as the father of microbiology and developed pasteurization, a process of gently heating liquids.
• Buchner demonstrated fermentation does not require living cells.
• Germ theory of disease was developed by Pasteur and further studied by Koch.
• Koch's work involved diseases like anthrax and established techniques for identifying bacteria, leading to Koch's postulates: suspect the causative agent, isolate it from the diseased host, and demonstrate that it causes disease when introduced to a healthy host.

Key Figures in Microbiology

• Semmelweis emphasized handwashing for infection control.
• Lister promoted antiseptic techniques in surgeries.
• Nightingale contributed to nursing practices.
• Snow was important in the epidemiology of infections.
• Jenner pioneered vaccination and immunology.
• Ehrlich introduced the concept of a "magic bullet" for chemotherapy.
• Beadle and Tatum established the relationship between gene activity and proteins.

Biotechnology and Applications

• Gene therapy involves inserting or repairing defective genes.
• Saccharomyces cerevisiae, a yeast, is essential in producing alcoholic beverages and leavened bread.
• Koch identified a bacterium as the cause of tuberculosis.
• Tobacco mosaic disease was the first described viral disease, affecting tobacco plants.