Exam 1 Study guide Microscopy Discovery of the very small Chapter 1 Robert Hooke Curator of experiments for the Royal society of London Took advantage of the early compound microscope s magnification ability and made detail studies of many living objects He described and drew the structure of a cork in his Micrographia which was published in 1665 Seeing a great deal of many boxes he called the spaces cella rooms and from that observation today we have the word cell Micrographia is one of the most important books b c it awakened the population to the world of the very small revolutionized the art of scientific investigation showed that the microscope was an important tool for unlocking the secrets of nature and opened the door to the world of the cell Leeuwenhoek From 1673 to 1723 he communicated his microscope observations through letters to England Royal Society 1674 a letter described a sample of cloudy water from a marshy lake and described hundreds of what he thought to be tiny living animals which he called animalcules Located even smaller animalcules in rainwater scrapings from his teeth and his poop In the 165 letters he sent he outlined structural details of yeast described thread like fungi and microscopic algae and protozoa The first to describe and illustrate the smallest living microbes the bacteria Do Animalcules arise spontaneously 1600s naturalists were vitalists and thought that life depended on a mysterious vital force in the air Witnessed toads that appeared from mud snakes coming from decaying humans and rats arising from A new generation of experimental naturalists arose garbage Francesco Redi In 1668 performed one of history s first biological experiments Designed to test the belief that worm like maggots arose from rotting meat Experiment verified spontaneous generation could not produce larger living organisms but what about the mysterious and minute animalcules that appeared to straddle the boundary b w the nonliving and living Could they arise spontaneously John Needham A British clergyman and naturalist Proposed that the spontaneous generation of animalcules resulted from a vital force that reorganized decaying matter Heated several flasks of animal broth and sealed the flasks with corks after they cooled After several days he proclaimed that the gravy swarmed with life with microscopical animals of most dimensios Convinced that purification could generate the vital force needed for spontaneous generation Lazzaro Spallanzani external air Rudolf Virchow Louis Pasteur Challenged Needhams conclusion and suggested that the animalcules came from the air and would therefore grow in the broth of the cooled flasks 1765 he repeated needhams experiments but w few changes He left some flasks open to the air others were closed loosely w corks the remaining were sealed All were boiled Concluded that the number of animalcules developed is proportional to the communication with the Needham and others countered that his experiments destroyed the vital force b c sealing of the flasks prevented the force from entering Controversy over spontaneous generation continued into the mid 1800s Put forth the idea of biogenesis life only arises from life French chemist and scientist took up the challenge in 1861 Experiments validated biogenesis Disease Transmission Can Be Interrupted Mid 1700s miasma bad air Vaccination Prevents Infectious Disease 1700s small pox was prevalent 1 3 of children died before 3 Since the 14th century Chinese have practiced variolation grounding small pox up and putting it under people nose etc 18th century Europeans started to put scabs under peoples skin Most only contracted a small form of small pox Edward Jenner Country surgeon whom learned that milkmaids who contracted cow pox didn t get small pox Hypothesized giving people cow pox would free them of the risk of small pox 1796 took a cow pox lesion from a milk maids hand and scratched it onto the skin of a young boys arm Boy developed slight fever Didn t get small pox 1798 Jenner repeated experiments with others verifying vaccination vacca cow Method of Vaccination spread throughout Europe Disease Transmission Does Not result from a miasma Ignaz Semmelweis after labor First epidemiological study which was instrumental to how disease was spread Was a Hungarian obstetrician who was shocked by the numbers of women dying of puerperal fever Revealed the disease was 20x more likely in the ward handled by med students Studies suggested that the disease transmission must be from the cadavers which med students were working on 1847 directed staff to wash hands in chlorine water before entering the maternity ward John Snow 1854 cholera epidemic Carried out one of the first epidemiological studies by interviewing the sick and healthy Results linked disease to sewage contaminated water supply Instituted the first known example of a public health measure to remove the street pump Proposed that cholera was water born and not air born The Stage Is Set Early years of the 1800s germ revolution 1830s advances in microscopes suggested these rod like organisms to be bacteria 1840 reported that living organisms could cause disease Christian Ehrenberg Jacob Henle Filippo Pacini Louis Pasture Discovered rod shaped cholera bacteria in stool samples from cholera patients Louis Pasteur Proposes That Germs Cause Infectious Disease Set to understand the process of fermentation Microscope observations consistently revealed large numbers of tiny yeast cells in fermented juice that were overlooked by other scientists He mixed yeast and sugar water in the absence of air yeast grew and converted the sugar to alcohol Demonstrated that wines beers and vinegar each contained diff types of microorganisms Wine souring only soured wines had bacterial cells Had reasons to believe that the spread of germs could be controlled wine disease problem heat the wine gently to kill bacteria but not effect wine Pasteurization Perhaps human infections can be caused by other microorganisms in the air germs Formulated germ theory of disease Joesph Lister L Pasteur More than half of amputation patients died Heard of the germ theory and then hypothesized that surgical infections resulted from germs in the air Wounds healed w o infection 1865 used carbolic acid spray in surgery and on surgical wounds Led to the practice of antisepsis Studied pebrine in silkworms Identified a new type of germ called corpuscular parasites 1865 cholera outbreak in Paris