Test 1_lecture_outline_Spring 12

Test 1_lecture_outline_Spring 12 - Chapter 1: Microbial...

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Chapter 1: Microbial Life: Origin and Discovery Microbiology- the study of organisms too small to be seen with the naked eye. Microorganisms are everywhere o Our bodies o Foods o Environments o Industry Some are pathogens but most are harmless or beneficial Importance? o Medicine Making antibodies Controlling disease Agriculture- o Nitrogen- fixing bacteria o Genetically engineered crops Food industry (make by the action of microorganisms) - beer, wine, bread, yogurt, pickles, chocolate! Genetic engineering o Insulin. Growth hormone, vitamins o Crops resistant to pests, heat, pesticides, herbicides, etc. Keep us alive o Recycle nutrients o Produce vitamins o Degrade organic matter Cause disease (most microbes are not pathogenic) o HIV, cold, STD’s, food poisoning, flu Microbiologists study: o Bacteria, viruses, protozoans, fungi, algae, diatoms, and more! Chapter 1: What Is a Microbe? Organism that requires a microscope to be seen Microbial cells size- 0.2um to mm; viruses much smaller Contradictions: Super-size cells - Thiomargarita namibiensis is size of fruit fly head _Microbial communities _ – in biofilms microbes have specialized functions & act as multicellular organism Viruses are non-cellular- considered to be microbes but are not fully functional cells 6 major groups studied by microbiologists Prokaryotes 1. Bacteria 2. Archaea (found in extreme environments) Eukaryotes 1. Algae 2. Protists 3. Fungi Viruses (own, different classification)
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Microbes Shape Human History Microbes affect food availability - Some destroy crops (corn rust, late blight- (thought to cause) Irish potato famine) - Some make foods (beer, bread, cheese) Microbial diseases change history Black plague in Europe killed 1/3 population in 14 th century Smallpox in Americas More soldiers have died from infections than battle wounds (no treatments or antibiotics) - _Florence Nightingale - convinced British govt to improve army TB (tuberculosis) in 19 th century AIDS today Discovery of Microbes Light microscope invented in 1600s Mid-1600s: Robert Hooke observes small eukaryotes with compound microscope 1 st to use term “cells” Antoni van Leeuwenhoek -1676: Built simple microscopes (only one lens) Described “wee animalcules” Published first drawings of bacteria (prokaryotes) Microbes Are Living Organisms Spontaneous generation -idea that living organisms originate form non-living matter (mice appear from recipe). Microbes arise only from other microbes No spontaneous generation 1861: Pasteur shows that microbes do not grow in liquid until introduced from outside He disproved this using broth in swan-necked flasks.
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Sterilized broth by boiling bent necks of flasks so that air could enter but microbes would be caught in neck. Led to development of methods for controlling growth of microorganisms
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Test 1_lecture_outline_Spring 12 - Chapter 1: Microbial...

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