Microbiology Exam 1 (Chapters 1, 3-5) Question and Answers

Microbiology Exam 1 (Chapters 1, 3-5) Question and Answers Microbiology Specialized area of biology that deals with organisms ordinarily too small to be seen without magnification. Microorganisms A living thing ordinarily too small to be seen without magnification. Classification Orderly arrangement of organisms into groups. Nomenclature System of assigning names. Binomial nomenclature Two-name system of naming organisms (Latin, Greek). Two names: Genus, species. It's always underlined or italicized. Genus first letter always capitalized, species not capitalized. Once it's been mentioned, the genus name can be shortened. Acellular organisms Viruses. Exist without a cellular structure. Cellular organisms Prokaryotes and Eukaryotes. Prokaryotes Organisms whose genetic material is not enclosed in membrane and lack specific organelles including a nucleus (bacteria). Eukaryotes Organisms whose genetic material is enclosed in nucleus (fungi, protozoa, algae). Prokaryotes versus Eukaryotes Prokaryotic cells are smaller than eukaryotic cells, and in addition to lacking a nucleus, they lack other complex internal compartments called organelles. All prokaryotes are microorganisms while only some eukaryotes are microorganisms (including algae, protozoa, molds and yeasts- and even anthropods). Binary fission The way bacteria reproduce. Splitting of a parent cell into two equal parts. Mycology The study of fungi. Phycology The study of simple photosynthetic eukaryotes (algae) ranging from single celled forms to large seaweeds. Pathogen Disease causing agents. Genetic engineering Manipulates the genetics of microbes, plants, and animals for the purpose of creating new products and genetically modified organisms. Recombinant DNA Switch DNA from one organism to another to design new organisms. Lactic acid bacteria Dairy products, yogurt and cheese. Curds Solid chunks of day old milk, (fats and proteins etc. used in cheese) and whey (mostly water). A gallon of milk yields only about 1.25 pounds of cheese (weight lost is water). Whey Liquid part of day old milk, mostly water. Rennin Turn caseinogens to casein. Curdling Products cause milk to separate into curds (the milk solids, fats, proteins, etc. Scientific method Approach taken by scientists to explain a certain natural phenomenon. Hypothesis A tentative explanation or statement to account for what is observed or measured. Theory Hypothesis backed by growing data. Spontaneous generation Life can rise from nonliving material. Cell theory All things are made of cells. Biogenesis the production of living organisms from other living organisms Fermentation Organisms convert sugar into alcohol or acid (vinegar). Using bacterial/fungal enzymes, convert food substrate from one form to another. Aid in slow food spoilage. Foods use it for flavor and other properties. Fermentation products include Lactic acid, acetic acid, yeast, etc. Pasteurization To kill organisms by heat, some spoiling agents still stay. Germ theory of disease Theory that microbes can invade other organisms and cause diseases. Koch's postulates Set of procedures to determine if a microbe causes a certain disease. Verified the germ theory of disease. Aseptic technique Aimed at reducing microbes in a medical setting and preventing wound infections. Lister proposed the idea of aspetic techniques and the importance of hand washing and equipment sterilization. Chemotherapy Treatment of disease by the use of chemical substances. Now problem with drug resistance. Synthetic drugs Chemical substances made in a lab. Antibiotics Chemical substance made by microbes. General sizes of macroscopic organisms? 1 mm Size of Microscopic organisms? 1 um to 100 um Size of Viruses? 10 nm to 100 nm What are the 3 domains used in the Woese-Fox system of classification? Bacteria, Archaea, Eukarya. Which domain are fungi members of? Eukarya Which domain are Protozoa? Eukarya Which domain are Algae? Eukarya Which domain are E. coli? Bacteria Which domain are Viruses? Neither Viruses Neither prokaryote or eukaryote; acellular. Very small (nm). Need an electron microscope to see them. Parasite. Core/caspid contains nucleic acids and a protein coat. Some envelope around caspids. Bacteria Prokaryote. All are microbes. Has a cell wall made up of Eubacteria peptidoglycan. Absorb nutrition. Reproduce by binary fission. Unicellular. Commonly found in biofilms. Algae Unicellular, some are multicellular. Reproduce asexually and sexually. Nutrition by photosynthesis. Cell wall made of cellulose. Fungi Some are unicellular, some are multicellular. Nonmotile. Reproduce by asexual and sexual reproduction. Cell wall made of chitin. Fungi digest outside then ingest, absorb by release enzymes into environment. Cell membrane made of ergosterol instead of cholesterol. Protozoa Unicellular. Reproduce sexually and asexually. No cell wall. Absorb nutrition. Use pseudopods, cilia and flagella for motility. Name 3 cellular structures protozoa use for locomotion Pseudopods, flagella, cilia. Be familiar with the ways that microorganisms are beneficial Part of food chain. Beneficially interact with other organisms in nature. Normal flora- vitamins. Help initial digestion of nutrients in rumen of stomach (primarily cellulose). Production of oxygen. Antibiotics, vaccine, medical advances). Be familiar with the ways that microbes affect the world. Found everywhere, part of the ecosystem (make greenhouse gasses, soil formation, mineral extraction), Nutrient recycling (CO2 and Nitrogen fixation). Decomposition. Interactions with other organisms- pathogens or beneficial. Mycology Study of fungi. Protozoology Study of protozoa. Virology Study of viruses. Phycology Study of simple photosynthetic eukaryotes. Morphology Study of detailed structure of microorganisms. Physiology Study of Microbial function. Taxonomy Classification/naming/ identification. Bacteriology Study of Bacteria. Microbial ecology Study of relationship between microbes and environment. What general metabolic process used by microbes aids in food production? Fermentation. Yeast A type of microscopic fungi that makes bread rise and ferments sugar to make alcoholic beverages. Why can cheeses have different tastes and properties even though they are all made from the lactic acid fermentation of milk? Different microbes give different flavors by different fermentation end products. What molecule found in yogurt makes it taste tart? Acetaldehyde. What causes holes to form in swiss cheese? Fermenting the remaining lactose & producing carbon dioxide bubbles in the cheese. How does wine become sour? Wine exposed to air and bacteria form acetic acid. Why did the study of microorganisms not officially begin until the 1500s? Microscope not developed until the 1500's. Hooke Coined the term "cell." Needham Spontaneous bacteria in heated broth with cover. Redi No flies from meat. Pasteur S-neck flask and aseptic technique. Vaccine for cholera and rabies. Schwann & Schleiden All living things are made of cells. Virchow Living cells come from preexisting cells. Lister Use carbolic acid sprayer (phenol) to sterilize surgical wounds and instruments to reduce infection. Semmelweis Hand washing during child birth by doctors. Jenner Vaccine for smallpox. Ehrlich Coined term "chemotherapy." Used the first synthetic chemo that did not damage tissue: Magic bullet. Flemming Penicillin from mold. Venter & Smith Complete sequence of bacterial genome. What are the three theories of how life emerged discussed in lecture? Cell theory, biogenesis, spontaneous generation. What were the major accomplishments of the Golden Age of Microbiology? Fermentation Pasteurization, Germ Theory, Vaccination. Why does milk spoil even if it is pasteurized? Some spoilage organisms stay. Name two foods that are pasteurized besides milk Eggs, Honey. What are the two types of chemotherapy? Synthetic drugs and antibiotics. Sterile Complete absence of viable microbes. Aseptic Prevent infection. Inoculation Cultivating (CULTURING) microorganisms by introducing a sample (INOCULUM) into a container of nutrient medium. Culture Observable growth that appears in or on the medium (cloudiness, colony) Incubation The medium is placed in a temperature-controlled chamber (INCUBATOR) to allow for growth that is observed macroscopically as growth on the plate surface or cloudiness in a liquid medium. Important because this is where cells have a chance to duplicate. Isolation Separate individual microbes and achieve isolated colonies