Microbiology (BIO 208) Exam 1 Study Guide Questions and Answers 100% Solved correctly

Define "Microbe" and discuss exceptions to the definition - Microbe: small microorganism that can cause fermentation or disease. -Found in 3 domains of life (Eukarya, Bacteria, and Archaea). Exceptions: some microorganisms and viruses does not fall within in these categories. -Viruses are acellular (not composed of cells) Compare and contrast the features of prokaryotes and eukaryotes - Prokaryotes: - Bacteria/Archaea -no membrane bound organelles -generally smaller Eukaryotes: - Protists -contain membrane bound organelles -DNA enclosed in organelles -generally larger Types of activities carried about by microbial cells - PROPERTIES OF ALL CELLS: 1)Metabolism -Genetic (replication, transcription, translation) -Catalytic (energy, biosynthesis) 2)Growth -Nutrients from the environment are converted into new cell materials to form new cells 3)Evolution -Cells evolve and develop new properties PROPERTIES OF SOME CELLS1)Differentiation -Some cells can form new cell structures such as a spore 2)Communication -Cells interact with each other by chemical messengers 3)Genetic Exchange -Cells can exchange genes by several mechanisms 4)Motility -Some are capable of self-propulsion Historical figures that contribute and are important in the genesis of the discipline of microbiology - Robert Hooke (): -The first to describe microbes. Antoni van Leeuwenhoek (): -The first to describe bacteria. Louis Pasteur (): -Disproved theory or spontaneous generation and discovered fermentation was a biologically mediated process. Ignaz Semmelweis: -Importance of hand washing and prevent transfer of disease between patients and physicians Joseph Lister: -Proper care or surgical wounds and the sterilization of surgical equipment Robert Koch (): -Developed techniques for obtaining pure cultures. -Demonstrated link between microbes and infectious diseases (EX: anthrax and tuberculosis) -Koch's Postulates Explain the role of pure cultures in the study of microbes and how to obtain them - -Using solid media is a way to obtain pure cultures -(Potato Slices),devised uniform and reproducible nutrient solutions solidified with gelatin and agar -Observed the masses of cells "colonies" (cell's morphology)Describe the evolution of microbial diversity in the Earth's natural history - -First self-replicating entities may not have been actual cells -Last universal common ancestor (LUCA): an ancestral cell which all modern cells come from Explain the application of Koch's postulates and challenges to their use - 1)The suspected pathogen must be present in all cases of the disease and absent from healthy animals. 2)The suspected pathogen must be grown in pure culture. 3)Cells from a pure culture of the suspected pathogen must cause disease in a healthy animal. 4)The suspected pathogen must be re-isolated and shown to be the same as the original. Challenge: microorganism have to be the same from the original and sometimes it is hard to obtained Discuss examples of how microorganisms significantly impact human life - -Microorganisms can be both beneficial and harmful to humans -Emphasis is typically on harmful microorganisms (infectious disease agents, or pathogens) -Many more microorganisms are beneficial than are harmful Ex: Microorganisms and the human gastrointestinal (GI) tract (good) Ex: Microorganisms and food (cause food spoilage and transmit disease) Discuss the application of Koch's postulates - Koch's postulates can be used to diagnose or microorganism that can cause disease. Describe the major functions of microbial cell membranes - Cytoplasmic Membrane: -highly selective membrane which enables nutrient/metabolites and excrete wastes. Functions: -Permeability Barrier---> prevents leakage -Protein Anchor --->transport -Energy Conservation ---> proton gradient Environment -Pressure-Temperature -pH Characteristics: -Fluidity -Permeability