05 04 natural sciences u2b

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05 04 natural sciences u2b

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Module 2B A World of Mystery Discoveries: Two Brilliant Minds He further showed that spoilage of perishable substances can be averted by destroying microorganisms to prevent contamination, resulting in the process of pasteurisation Pasteur demonstrated that wine and beer could be preserved by heating above 57.2º C (135º F) for a few minutes Pasteurisation of milk, widely practised in several countries, requires temperatures of about 63º C (145º F) for 30 minutes or, alternatively, heating to a higher temperature, 72º C (162º F) for 15 seconds An accidental discovery The Hungarian physician Ignaz P Semmelweis (1818-1865) greatly reduced the incidence of puerperal fever through his pioneering work in antiseptic techniques Realising that physicians in certain wards of Vienna hospitals carried the disease from the autopsy room and transmitted it to women in the maternity ward, Semmelweis ordered all physicians in his service to wash their hands thoroughly before examining patients Semmelweis himself died of puerperal fever before his views were widely accepted Adapted from: http://gi.grolier.com/encyclopedia Activities 1 State if the following sentences are true (T) or false (F) a According to Pasteur’s studies, fermentation depends on living germs b Wine and beer can’t be preserved by heating above 57.2º C c Specific germs cause many diseases d Pasteur was the first to argue that infectious diseases were caused by germs e Semmelweis made puerperal fever disappear completely through his antiseptic techniques English Toolkit - Natural Sciences Photocopiable © Ediciones Santillana S.A / Richmond 2011 The scientific contributions of Louis Pasteur (1822-1895), French chemist and microbiologist, were among the most valuable in the history of Science While he was not the first to argue that infectious diseases were caused by germs, his work was of paramount importance in demonstrating the relevance of germ theory to infectious disease, surgery, hospital management, agriculture and industry In the early 1860s, he began working on fermentation Studies of the industrial fermentation of beet juice led him to the hypothesis that fermentation was dependent on living germs or ferments Pasteur demonstrated that yeast was a microorganism that converts sugar into alcohol In History of Lactic Acid Fermentation, Pasteur stated that certain kinds of fermentation were caused by the activities of specific microscopic living organisms and that many diseases were also caused by particular germs Thus, he laid the foundation for the germ theory of disease These studies had great economic significance as well, because they provided a means of gaining some control over the production of wine, beer and vinegar Module 2B f The disease was spread through examining patients in the maternity ward g Physicians had to wash their hands carefully before examining patients h Semmelweis died of puerperal fever being well known for his work in antiseptic techniques 2 Read the text again and find synonyms for these words a b c d e f g h doctor: temperature: investigation: methods: illness: instructed: thoroughly: ideas: 3 Complete this information about Pasteur Photocopiable © Ediciones Santillana S.A / Richmond 2011 Name: Born in: Died: Nationality: Occupation: Theory: Early 1860s: Demonstration: Discovery: 4 Write about Pasteur using the information provided in activity 5 Find out information about three different personalities who made important discoveries and / or were awarded a Nobel Prize in your country Write a paragraph about one of them Include a photo of the personality if you want English Toolkit - Natural Sciences

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