Microbiology Study Guide PDF

# Three Domains: ## Archaea - Kingdom Archeabacteria: - Unicellular. - Prokaryotes. - Some autotrophic; others heterotrophic. - Different from bacteria in structure and chemicals. - Cell walls of different compositions. - Known as: Ancient bacteria. Extremophiles. ## Eubact...

# Three Domains: ## Archaea - Kingdom Archeabacteria: - Unicellular. - Prokaryotes. - Some autotrophic; others heterotrophic. - Different from bacteria in structure and chemicals. - Cell walls of different compositions. - Known as: Ancient bacteria. Extremophiles. ## Eubacteria - Kingdom Eubacteria: - Found everywhere, except: extreme environments. - Unicellular. - Prokaryotes. - Some autotrophic, others heterotrophic. - Cell wall: made of peptidoglycan. ## Eukaryota ### Kingdom Protista: - Contain any organism not classified as animal, plant, or fungus. - Eukaryotic. Most unicellular, other multicellular. - Some autotrophic, others heterotrophic. - Some have a cell wall. - Ex: Euglena. Amoeba. Volvox. Paramecium. ### Kingdom Fungi: - Eukaryotic. Most multicellular. Yeast unicellular. - Heterotrophic. - Cell wall: chitin. - Ex: molds. Mushrooms. ### Kingdom Plantae: - Multicellular. - Eukaryotic. Autotrophic. - Most live on land. - Cell wall: cellulose. ### Kingdom Animalea: - Multicellular. - Eukaryotic. Heterotrophic. - Live in diverse environments. --- # Robert Hooke: - Father of Microbiology. - First one to use a microscope. # Louis Pasteur: - Microbes caused fermentation. - Introduced pasteurization to prevent spoilage. - Developed the aseptic technique, which uses cotton to prevent air contamination. # Robert Koch: - Used experiments called "Koch's postulates," to prove that bacteria cause anthrax." - First one to use agar as a solid medium. # Paul Ehrlich: - Prepared the arsenic compound called salvarsan, which is effective against syphilis bacteria. # Alexander Fleming: - Discovered penicillin. # Fransesco Redi: - Showed maggots developing in putrefying meat are the larval stage of flies. - Developed the control experimental method. # Microorganisms Importance: - Transformation of matter. - Nitrogen Fixation. - Biogas. - Industrial Uses. - Biological Control. - Causing Diseases. --- # Cell Wall: - Protects and maintains the shape of organisms. - Bacteria cell wall made up of peptidoglycan, commonly known as murein. - Peptidoglycan made of 2 amino sugars: NAG and NAM. ## Gram-Positive: - Have interpeptide bridges that join amino acid side chains together. - Cell wall: thick (20 - 80 nm). - Several layers of peptidoglycan (more than 60%). - Teichoic Acid: - Runs perpendicular to peptidoglycan. - Unique to G-positive. - Links to peptidoglycan. - Provides strength to the cell wall. - Polymers of glycerol or ribitol. - Joined by phosphate group. - Lipoteichoic acid: links to plasma membrane (0-3%). ## Gram-Negative: - Cell wall: thin (10 nm). - Single layer of peptidoglycan. - Lipopolysaccharide: unique to G-negative. - Endotoxin. - Toxic to animals. - Porins: form channels through the membranes. # Mycoplasma: - Group of smallest organisms. - Pass through bacterial filters. - Lack of cell wall. - Plasma membrane have sterols. - Shape: Pleomorphic, spherical, short-rod, filament. - Resistant to antibiotics: penicillin, cephalosporins, vancomycin - Causing diseases: pneumonia, pharyngitis. # Extremophiles: - Thermophilic Archaea. - Halophilic Archaea. - Methanogenic Archaea. # Actinobacteria: - G-positive bacteria. - High content guanine - cytosine in DNA. - Found in aquatic and terrestrial habitats. - Filamentous bacteria, but form mycelium: - Non-septate. - Usually slender. - Produce: Hyphae. Spores. # Eubacteria: - Cell wall: Peptidoglycan. - Linkage: Ester linked. - Prokaryotes - Unicellular - Have 70S ribosomes - Some of them are "Pathogens". # Archeabacteria: - Cell wall: No peptidoglycan. - Linkage: Ether linked. - Prokaryotes - Unicellular - Have 70S ribosomes - Some of them are "Pathogens". # Importance of Microorganisms: - **Produce secondary metabolites:** have pharmacological and commercial interest. - Streptomyces produce antibiotics. - **Decomposition** of organic substances, including: Cellulose, chitin, fats, organic acids. - **Humus** in soil / healthy smell of geosmins. # Bacteria at use: - Cotton seedling root growth. - Bean seedling growth.