BIOL 211L Study Guide Quiz #1 - Microbiology Study Guide

Lecture 1 ​ What is microbiology? ○​ The study of all living organisms that are too small to see with the naked eye (bacteria, archaea, fungi, viruses, etc) Safety in the Lab ​ What goes in the sharps container vs biohazard vs regular trash? ○​ Sharps co...

Lecture 1 ​ What is microbiology? ○​ The study of all living organisms that are too small to see with the naked eye (bacteria, archaea, fungi, viruses, etc) Safety in the Lab ​ What goes in the sharps container vs biohazard vs regular trash? ○​ Sharps container: ​ SHARP OBJECTS ONLY ​ needles, glass slides & cover slips, broken glass, Pasteur pipettes, syringes ○​ Biohazard: ​ For soft contaminated objects ​ Paper towels, cotton, tongue depressor, plastic petri dishes, ALL gloves ○​ Regular trash: ​ Anything that is not contaminated ​ Paper towels for washing hands, etc ​ Necessary PPE: ○​ Lab coat, safety glasses/goggles ​ Cleaning up a spill ○​ If a big spill, notify TA ○​ If bacteria, blood, or fungi are spilled: 1.​ Cover the area with paper towels, and gently flood with Amphyl 2.​ After 20 min, clean carefully *place broken glass in sharps containers and paper towels in the step-on can ​ Cleaning up the bench ○​ Put supplies away & equipment ○​ Put microscopes away and ensure they're clean, and put on the lowest magnification & stage back ○​ Make sure burners are off ○​ Disinfect desk with amphyl & paper towels ○​ Empty gram stain waste and pipette tips waste ○​ Wash your hands!  ​ DO’s ○​ Keep hair tied back ○​ Wear lab coats at all times ○​ Keep bags and books on the floor by leg holes ○​ Use shields when conducting procedures involving fluids ○​ Wear safety goggles and gloves when working with chemicals (no contacts) ○​ Know which chemicals are hazardous ​ DON’T ○​ Wear dangling jewelry ○​ Wear sandals ○​ Mouth pipette ○​ Discard anything that is not yours ○​ Apply makeup in class (including chapstick) ○​ Vape, chew tobacco, etc Microscopy ​ Define total magnification: ○​ Multiply objective magnification and eyepiece magnification ○​ Our eyepiece magnification is 10x ​ Define resolving power: ○​ Ability to distinguish between two very small and closely spaced objects on a specimen as separate entities ○​ Closer = higher resolving power needed ​ Define Numerical aperture: ○​ Measure of the objective ability to capture light and resolve fine specimen detail at a fixed object distance ○​ Refractive index: degree that light is bent as it passes from one medium to another ○​ The larger the numerical aperture, the higher the resolution and the brighter ​ Why and when do we do oil immersion? ○​ It bends more light into the lens to capture more “image information” ​ The refractive index of oil = 1.5; air = 1 ○​ More “image information” = higher resolution ​ See finer details ○​ 100x is the only lens that can come into contact with oil ​ Types of microscopes: ​ when would you use them and their main characteristics ○​ Brightfield microscope ​ The object is dark in a bright field ​ Good for viewing stained specimens ​ Living objects in wet mount may appear washed out ○​ Darkfield microscope ​ A special condenser causes light to be reflected off the specimen ​ The object is light on a dark background ​ Very good for observing unstained live specimens ○​ Phase contrast microscope ​ Use refracted and un-refracted light waves to enhance the contrast of the specimen (no staining) ​ Different refractive indices ​ Makes internal structure visible!! ○​ Fluorescence microscope ​ For detecting microbes in tissues and other samples ​ Samples must be specially stained to make them fluoresce ​ Irradiated with light of specific wavelength ​ A high degree of specificity ○​ Stereomicroscope ​ Good for observing large objects, like colonies of bacteria & fungi ​ Study the surfaces of solid specimens & carry out close work ​ Used 2 eyepieces & 2 objectives ○​ Different viewing angles to the left and right eyes ​ Produce a 3d visualtioion of the sample ○​ Electron microscopy ​ Uses electrons instead of light to visualize an image ​ Performed in vacuum ​ Higher resolving power ​ Electromagnetic lenses are used to control the electron beam and focus it to form an image ​ Different types of EM ​ Transmission electron microscopy (TEM) ○​ Electrons pass through a very thin section of material  ○​ Specimen is in part transparent to electrons and in part scatters them out of them beam ○​ Scattered electrons are collected in the magnetic lens & a computer creates an image from the electron “pattern” ​ Scanning electron microscopy ○​ Produces images by probing the specimen with a focused electron beam ​ The electron beam interacts with the specimen and loses energy ​ Scanned across a rectangular area of the specimen (raster scanning) ​ 3D image, see outside structure ​ Protozoa: ○​ Protist kingdom ○​ SINGLE-celled eukaryoes ○​ Most lack cell walls ○​ Uses organic C for growth by consuming other organisms ○​ Some are human parasites ○​ Classified base don their means of locomotion: ​ Flagellates ​ Ciliates ​ Ameboids ​ Algae: ○​ Eukaryotes ○​ Unicellular or multi cellular ○​ Photosynthesis with chloroplasts (autotrophic) ○​ Photosynthesis with chloroplats (autotrophic) ○​ Ex → diatoms or dinoflagellates ​ Eubacteria: ○​ Prokaryotic microorganisms ○​ Mostly unicellular ○​ Large group; extremely diverse ○​ Lack a nucleus ​ DNA is a single circular chromosome  ​ Cyanobacteria: ○​ Most are colonies (filaments or hollow ball) ○​ Oxygen producing prokaryotes ​ Known as blue green algae ​ Most obtain their energy through photosynthesis ​ Important in nitrogen fixation ​ Take atmospheric N and incorporate into organic compounds ​ What is hay fusion? ○​ Soaking dried plant material (hay) in water ○​ Rehydration of cysts/endospores from dormant microbes in the hay ○​ Bacteria will appear first and most abundant ○​ Later: protozoa consumer bacteria, and appearance in the food chain depends on pH, light, temp, etc Fungi and Yeast ​ 2 sep classes of fungi: unicllulae vs. multicellular ​ 4 subclasses of multicellular fungi based on hyphae & spores ○​ Zygomycota ​ Rhizopus, bread molds, mucor ○​ Ascomycota ​ Neurospora, yeast, sac, fungi ○​ Basidiomycota ​ Mushrooms, rusts, smuts ○​ Deuteromycota ​ What are hyphae and how are they structured? ○​ Fungi grow extensions of hyphae, they absorb nutrients ○​ Reproduce sexually and/or asexually ○​ Aeriel hyphae (on surface) often produce conidia ​ Conidia enclosed in a sac (the sporangium) = endospores ​ Sexual reproduction ○​ Two contributing genetic material ​ Asexual reproduction ○​ Offspring created by a single parent ​ How is yeast classified? ○​ Unicellular fungi ​ How does yeast reporudce? ○​ Asexually by budding (breaks off) or fission (division resulting in two new cells)  ○​ What are yeasts main characteristics?​ ​ Unicellular fungi & Can form pseudohyphae ​ What are opportunistic pathogens? ○​ Pathogens → microbes that can cause disease in healthy people ○​ Opportunisitc pathogen → if the host is health, the microbe usually doesnt cause disease ​ If hosts immune system is supressed or compormised, the microbe invased body ○​ What type of hosts do they invade?​ ​ Compromised immune systems Morpholgy of Bacteria ​ How are bacteria identified? Shape? Main characteristics? ○​ Cocci (spherical or round), bacilli (rectanular or rod shaped), spirilla (curved or helical), vibrio (curved rod or comma shaped), spirochete (corkscrew shape) ​ What is the aseptic technique? ○​ Process of growing bacteria in pure cultures ​ Why do we use the aseptic technique? ○​ Avoid contaminutaion of unwanted organisms, safety reason ​ What do we use in aseptic technique? ○​ Inoculation loop: used to transfer liquid cultures, picking a large bacterial colony off a plate, streaking bacteria on agar surfaces ○​ Busen burner: steralize the material, create sterile field, tip of the inner cone is the hottest part Culture Media ​ Pure: contains a single species of microbe ​ Contaminated: introduction of unwanted microbes into a culture ​ Inoculated: introduction of a microbe into/on culture media ​ What does media usually contain? ○​ Water, carbon, nitrogen, minerals, and growth factors ○​ Specific pH levels ​ Main types of media ○​ Agar: galactose sugar polymer – ideal for solid media, incubation at 37 degrees ○​ General purpose: grow variety of different microorcanisms – nutrient agar ○​ Selective: only allows certain bacterial growth – columbia media ○​ Differential: contains substances that cause bacteria to take a diff appearance from diff species – EMB, Blood agar plates (BAP) Smear Preperation ​ What is a smear? ○​ Thin layer of specimen on a glass slide ○​ Used to transer bacteria on microscope slides ​ Staining technique ​ What is smear prep and when would you use this? ○​ Used to transfer bacteria on microscope slides ​ Smear prep: broth ○​ Use inoculation loop ○​ Advantage; easier to make smear ○​ Disadvantage: difficult to control the quantity of microbes transferred ​ Smear prep: agar ○​ Apply a drop of DI water to the slide ○​ Use an inoculation needle ○​ Advantage: easer to control the quantity of microbes transferred ○​ Disadvantage: could easily add too much of the culture microbe (too dense) ​ Heat fixing ○​ Important step of smear prep ○​ Allow bacteria on slide to be completely dry ○​ Pass slide over bunsen burner pass it quickly ⅔ times L shape to KILL the bacteria, and ascertain the bacteria adhere to the slide ​ What is simple staining? ○​ Bacteria are very small and transparent, the dye is used to analyze specific characteristics ○​ Staining improves the contrast between specimen an background ○​ Allows us to observe morphology and arrangement ​ Chemistry of staining ○​ Most bacteria have cytoplasmic membernaes that are anionic (negative charge) ○​ Many dues will be molecules that are cationic (positively charged) ○​ Opposite charges attract ​ Dye molecule will ionically bind to the membrane, effectively coating htem with color