module 2

• Cellular and Acellular members of the microbe world include Bacteria, Eukaryotes (Protists), Archaea, and Funghi.
• Acellular members of the microbe world include Viruses, Viroids, Satellites, and Prions.
• Major types of bacteria include Gram negative, which have an outer lipid membrane, and Gram positive, which do not have an outer lipid membrane but have a thick peptidoglycan cell wall.
• Bacteria lack membrane-bound organelles.
• Archaea have a different set of rRNA, ether bonds in lipid in cell wall, do not have peptidoglycan, and have unusual metabolic characteristics.
• Fungi are used in fermentation, acid production, and medication.
• Algae, Protozoa, Slime molds, and Water molds are types of Protists.
• Protists are characterized as being large and unicellular, lacking tissue organizations of higher eukaryotes.
• The structure of acellular organisms includes Viruses, which consist of DNA and proteins, Viroids, which consist of RNA, Satellites, which consist of nucleic acids, and Prions, which consist of proteins.
• Agar contains Tryptone as a source of protein, NaCl, Yeast extract as a source of vitamins, proteins, and nitrogen, and Agar.
• Spread plates involve spreading a mixture of cells on an agar surface so that individual cells are well separated from each other.
• A microscope uses lenses to bend light towards the eye to enlarge the image.
• The objective lens of a microscope is located above the microorganism, and the ocular lens is closer to the eye.
• Magnification makes the object larger, while resolution makes the object clearer.
• The magnification of the objective lens is multiplied by the magnification of the ocular lens.
• Resolution is the minimum distance between two objects which still allows them to be distinguished as separate objects.
• To improve resolution, minimize light refraction by using lens oil and increase the range of angles over which the microscope can affect light by bringing the microscope closer to the object.
• Binary fission, Budding, and Filamentous growth are examples of three types of cell division.
• Heat fixation is used on prokaryotes and uses heat from a Bunsen burner to kill and fix the bacteria to the glass, preserving general morphology but destroying internal structures.
• Staining is used to enhance contrast of the image and binds to cells via ionic, covalent or hydrophobic bonds.
• The log phase formula is g=t/n, where n is the generation time, and the formula for generation time is n = (log(Nt)-log(N0))/0.301.
• Turbidity measurement is an example of an indirect measurement, and its pros and cons include being quick, easy, and sensitive, but it cannot distinguish between dead and alive cells and becomes inaccurate after a certain OD is reached.
• Absorbance measures how much light of a specific wavelength is absorbed by molecules in a solution, 254nm for DNA, 280nm for proteins, 400-500nm for cytochromes.
• Chemical fixation is used for larger organisms and uses chemicals, such as formaldehyde, to preserve the internal structure of the organism.
• Diplococci, Staphylococci, Streptococci, Tetrad, and Sarcina are examples of microbial arrangements for cocci.
• There are four types of bacterial shapes: Cocci (Sphere shaped), Bacilli (rod shaped), Spirales (spiral shaped), and Filamentous (go figure).
• Cell growth can be measured using the direct method, indirect method, and cell plate count.
• Counting chambers are an example of a simple direct measurement, and their pros and cons include being easy to observe and distinguish between live and dead cells, but they require experience and expertise to do it accurately.
• Electronic counters are an example of an advanced direct measurement, and their pros and cons include being automated but not being able to differentiate between dead and alive cells.
• Coccobacillus, Palisades, Bacillus, Streptobacilli, and Diplobacilli are examples of microbial arrangements for bacilli.
• Viable Plate Counting uses serial dilution, followed by plate spreads, to enumerate number of colony forming units.
• Optical density measures how much light is scattered, rather than absorbed, by the bacteria, typically around 600nm.
• Kohler Illustration involves using a field diaphragm to eliminate extraneous light and focus the light from a light bulb, and an aperture diaphragm to achieve optimal alignment by focusing light angle.
• Microorganisms are the most populous group of organisms and are found everywhere on the planet, containing 50% of the biological carbon and 90% of the biological nitrogen.
• Experiment 2 & 3 require a full lab report including both answering the questions provided at the end of each Lab manual and “Title, Summary, Introduction, Materials and Methods, Results and discussions, References”.
• Microorganisms play a major role in recycling essential elements, serving as a source of nutrients and some carry out photosynthesis.
• Microorganisms benefit society by their production of food, beverages, antibiotics and vitamins.
• Microorganisms can also be causative agents of some infectious diseases.
• Microbiomes are closely related to human health, physiology, and metabolism.
• The emerging frontier in Biomedical Sciences is Microbiota, with 100 trillion (10^14) microbial cells harbored in the human body.