{"id":1461,"date":"2013-03-29T04:59:31","date_gmt":"2013-03-29T04:59:31","guid":{"rendered":"http:\/\/iteach.ro\/experientedidactice\/?p=1461"},"modified":"2019-10-11T07:46:26","modified_gmt":"2019-10-11T04:46:26","slug":"experimentul-biologic-sau-stiinta-in-propria-bucatarie","status":"publish","type":"post","link":"https:\/\/iteach.ro\/experientedidactice\/experimentul-biologic-sau-stiinta-in-propria-bucatarie","title":{"rendered":"Experimentul biologic sau \u0219tiin\u021b\u0103 \u00een propria buc\u0103t\u0103rie"},"content":{"rendered":"<p>\u00cen 2011, am avut ocazia s\u0103 particip la o activitate de formare printr-un grant Comenius-LLP. Cursul a avut loc la Cheltenham-Anglia, unde se desf\u0103\u0219ura un festival al \u0219tiin\u021belor. Mi s-a oferit oportunitatea de a vizita c\u00e2teva \u0219coli \u0219i de a discuta cu profesorii de \u0219tiin\u021be. M-am \u00eentors entuziasmat\u0103 \u0219i hot\u0103r\u00e2t\u0103 s\u0103 pun \u00een practic\u0103 c\u00e2teva idei. V\u0103 prezint aici un experiment simplu, care poate fi realizat doar cu \u201dinstrumentele\u201d din buc\u0103t\u0103rie. Proiectul poate fi folosit la o activitate \u00eentr-un centru de excelen\u021b\u0103 sau chiar la ora de biologie. Am \u00eencercat s\u0103 \u00eembin strategiile tradi\u021bionale cu cele moderne, aplic\u00e2nd principiile \u015fi strategiile instruirii diferen\u0163iate. Avantajul aplic\u0103rii unui astfel de experiment este faptul c\u0103 orice elev \u00eel poate reproduce \u00een propria familie, f\u0103c\u00e2nd-o astfel p\u0103rta\u0219\u0103 la educa\u021bia oferit\u0103 de \u0219coal\u0103.<br \/>\n<!--more--><\/p>\n<p><strong>Extragerea ADN din fructul de kiwi<\/strong><\/p>\n<p>Resurse: instruc\u021biuni experiment; materialele necesare experimentului; bomboane, scobitori; calculator, videoproiector.<\/p>\n<p>SCENARIUL DIDACTIC<\/p>\n<p><strong>1. Captarea aten\u0163iei.<\/strong><br \/>\nPrezentarea filmului (4 min) \u201dCe te face pe tine s\u0103 fii tu?\u201d\u00a0care se poate desc\u0103rca de la adresa: http:\/\/www.youtube.com\/watch?v=bVk0twJYL6Y.<br \/>\n<iframe loading=\"lazy\" src=\"http:\/\/www.youtube.com\/embed\/bVk0twJYL6Y?rel=0\" width=\"640\" height=\"360\" frameborder=\"0\"><\/iframe><\/p>\n<p>Discutarea rolului, localiz\u0103rii, structurii ADN (film 3 min http:\/\/www.youtube.com\/watch?v=S8DMoDJ8FWA)<br \/>\n<iframe loading=\"lazy\" src=\"http:\/\/www.youtube.com\/embed\/S8DMoDJ8FWA?rel=0\" width=\"640\" height=\"480\" frameborder=\"0\"><\/iframe><\/p>\n<p><strong>2. Conducerea \u00eenv\u0103\u0163\u0103rii:<\/strong><br \/>\nExtragerea ADN\u00a0 (lucru pe grupe).<\/p>\n<p>FI\u0218A DE LUCRU A EXPERIMENTULUI<\/p>\n<p>Materiale necesare: kiwi, mojar, 5g detergent de vase lichid, 2g sare, 100 ml ap\u0103, 100 ml alcool metilic rece, fierb\u0103tor, termometru, crati\u021b\u0103, blender, h\u00e2rtie de filtru, cu\u021bit.<\/p>\n<p>Etapele experimentului:<br \/>\n1 &#8211; Coji\u021bi un kiwi; t\u0103ia\u021bi-l \u00een buc\u0103\u021bi mici (blender). Celulele care formeaz\u0103 coaja sunt majoritatea moarte, nu mai con\u021bin suficient de mult ADN.<br \/>\n2 &#8211; Pune\u021bi buc\u0103\u021belele de kiwi \u00een mojar \u0219i zdrobi\u021bi-le bine. Aceast\u0103 opera\u021bie permite distrugerea unor celule determin\u00e2nd cre\u0219terea suprafe\u021bei de pe care vom extrage ADN.<br \/>\n3 &#8211; Amesteca\u021bi \u00eencet detergentul de vase, sarea \u0219i apa p\u00e2n\u0103 c\u00e2nd sarea s-a dizolvat complet, evit\u00e2nd formarea de bule. Aceast\u0103 mixtur\u0103 se mai nume\u0219te <em>buffer<\/em>.<br \/>\n4 \u2013 Ad\u0103uga\u021bi <em>bufferul<\/em> peste fructele zdrobite \u0219i amesteca\u021bi foarte bine. Cu c\u00e2t amesteca\u021bi mai bine, cu at\u00e2t mai mult ADN ve\u021bi ob\u021bine \u00een final.<br \/>\n5 \u2013 \u00cenc\u0103lzi\u021bi solu\u021bia ob\u021binut\u0103 p\u00e2n\u0103 la 60 de grade C astfel: lua\u021bi un vas mare umplut pe jum\u0103tate cu ap\u0103 fiart\u0103 cu ajutorul unui fierb\u0103tor. Pentru a o aduce la temperatura dorit\u0103, turna\u021bi pu\u021bin\u0103 ap\u0103 rece \u00een vas. A\u0219eza\u021bi cu grij\u0103 vasul \u00een care a\u021bi amestecat fructele de kiwi cu solu\u021bia tampon de extragere \u00een apa \u00eenc\u0103lzit\u0103. L\u0103sa\u021bi 15 minute. Pere\u021bii celulari se vor distruge \u0219i va \u00eencepe degradarea proteinelor celulare.<br \/>\n6 \u2013 Scoate\u021bi vasul cu kiwi \u0219i filtra\u021bi mixtura prin h\u00e2rtia filtrului de cafea.\u00a0 Ve\u021bi ob\u021bine un lichid verde care con\u021bine ADN.<br \/>\n7 \u2013 Turna\u021bi \u00eencet alcoolul rece pe peretele vasului. Se formeaz\u0103 o pelicul\u0103 de alcool deasupra mixturii de kiwi deoarece acesta are densitate mai mic\u0103. Observa\u021bi sub stratul de alcool\u00a0 formarea unei substan\u021be alb-gelatinoase (ADN). Extrage\u021bi ADN-ul folosind o agraf\u0103 de birou.La finalul experimentului discut\u0103m: toate organismele sunt formate din celule care con\u021bin \u00een nucleu ADN.\u00a0 Extragem ADN din orice celul\u0103 vie dup\u0103 ce distrugem peretele celular. \u00cen prezen\u021ba alcoolului ADN-ul se coaguleaz\u0103 form\u00e2nd o mas\u0103 gelatinoas\u0103 albicioas\u0103.<\/p>\n<p><strong>3. Fixarea.<\/strong><br \/>\nAsocia\u021bi explica\u021biile proceselor\u00a0 produse \u00een timpul experimentului cu imaginile potrivite (se dau copiilor cartona\u0219e cu textele de mai jos \u0219i cartona\u0219e cu imagini):<\/p>\n<p>\u201dCelulele plantelor sunt \u00eenconjurate de pere\u021bi celulari \u0219i de membrane formate din lipide\/gr\u0103simi. Fiecare are un nucleu \u00een care este localizat ADN-ul.\u201d (imagine: celule epiteliale cu prete\u021bii celulari contura\u021bi cu alt\u0103 culoare, asem\u0103n\u0103toare celor care se pot observa la microscop c\u00e2nd observ\u0103 foi\u021bele de ceap\u0103)<\/p>\n<p><a href=\"http:\/\/iteach.ro\/experientedidactice\/wp-content\/uploads\/2013\/03\/image002.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1467\" title=\"image002\" src=\"http:\/\/iteach.ro\/experientedidactice\/wp-content\/uploads\/2013\/03\/image002.png\" alt=\"\" width=\"211\" height=\"103\" \/><\/a><\/p>\n<p>\u201dTemperatura ridicat\u0103 rupe pere\u021bii celulari expun\u00e2nd membrana.\u201d (imagine: acelea\u0219i celule dar cu pere\u021bii fragmenta\u021bi)<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1468\" title=\"image004\" src=\"http:\/\/iteach.ro\/experientedidactice\/wp-content\/uploads\/2013\/03\/image004.png\" alt=\"\" width=\"211\" height=\"99\" \/><\/p>\n<p>\u201dDetergentul de vase dizolv\u0103 lipidele membranei.\u201d (imagine: aglomer\u0103ri de ADN izolate\u00a0printre care se v\u0103d fragmente de membrane celulare\u00a0\u0219i nucleare)<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1469\" title=\"image006\" src=\"http:\/\/iteach.ro\/experientedidactice\/wp-content\/uploads\/2013\/03\/image006.png\" alt=\"\" width=\"211\" height=\"106\" \/><\/p>\n<p>\u201dDeoarece celulele con\u021bin enzime care \u201drup\u201d proteinele, acestea \u00eencep s\u0103 fie distruse. Sarea face ca moleculele\u00a0 ADN s\u0103 se lipeasc\u0103 unele de altele. ADN-ul nu se dizolv\u0103 \u00een alcool coagul\u00e2ndu-se, d\u00e2nd na\u0219tere substan\u021bei gelatinoase albe.\u201d (imagine: aglomer\u0103rile ADN din imaginea precedent\u0103 dar lipite unele de altele)<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1470\" title=\"image008\" src=\"http:\/\/iteach.ro\/experientedidactice\/wp-content\/uploads\/2013\/03\/image008.png\" alt=\"\" width=\"206\" height=\"121\" \/><\/p>\n<p>\u201dADN-ul\u00a0 extras provine din miliarde de celule de kiwi, de aceea a putut fi observat u\u0219or. Extr\u0103g\u00e2nd ADN dintr-o singur\u0103 celul\u0103 uman\u0103 \u0219i \u00eentinz\u00e2ndu-l, am ob\u021bine un firi\u0219or de 2 m lungime.\u201d (imagine: structura ADN)<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1472\" title=\"image010\" src=\"http:\/\/iteach.ro\/experientedidactice\/wp-content\/uploads\/2013\/03\/image010.jpg\" alt=\"\" width=\"280\" height=\"121\" \/><\/p>\n<p>Apoi se \u00eemparte clasa \u00een grupe, \u00een func\u0163ie de tipul de inteligen\u0163\u0103 predominant \u0219i de nivelul cuno\u0219tin\u021belor.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignright size-full wp-image-1473\" title=\"image012\" src=\"http:\/\/iteach.ro\/experientedidactice\/wp-content\/uploads\/2013\/03\/image012.jpg\" alt=\"\" width=\"301\" height=\"175\" srcset=\"https:\/\/iteach.ro\/experientedidactice\/wp-content\/uploads\/2013\/03\/image012.jpg 301w, https:\/\/iteach.ro\/experientedidactice\/wp-content\/uploads\/2013\/03\/image012-300x174.jpg 300w\" sizes=\"auto, (max-width: 301px) 100vw, 301px\" \/>Fiecare grup\u0103 va primi urm\u0103toarele sarcini de lucru:<br \/>\nGr.I \u2013 Inteligen\u0163\u0103 lingvistic\u0103<br \/>\n<em>Realiza\u021bi o scurt\u0103 pies\u0103 de teatru\/eseu \u00een care s\u0103 explica\u021bi importan\u021ba ADN \u00een via\u021ba organismelor.<\/em><br \/>\nGr.II \u2013 Inteligen\u0163\u0103 spa\u0163ial-vizual\u0103<br \/>\n<em>Construi\u021bi un dublu helix ADN din bomboane.<\/em><br \/>\nGr. III- Inteligen\u0163\u0103 \u0219tiin\u021bific\u0103<br \/>\n<em>Elabora\u0163i un suport vizual (ppt) pentru o prezentare cu tema \u201dADN \u0219i diviziunea celular\u0103\u201d.<\/em><\/p>\n<p><strong>4. Evaluare:<\/strong><br \/>\nExpun mostrele ADN ob\u021binute \u00een experimente\/modelele ADN construite \u0219i celelalte produse ale activit\u0103\u021bii desf\u0103\u0219urate pe grupe.<\/p>\n<p>BIBLIOGRAFIE:<br \/>\n<a href=\"http:\/\/www.thenakedscientists.com\/HTML\/content\/kitchenscience\/\" target=\"_blank\" rel=\"noopener noreferrer\"> http:\/\/www.thenakedscientists.com\/HTML\/content\/kitchenscience\/<\/a><br \/>\n<a href=\"http:\/\/codecereal.blogspot.ro\/2011_05_01_archive\" target=\"_blank\" rel=\"noopener noreferrer\"> http:\/\/codecereal.blogspot.ro\/2011_05_01_archive<\/a><br \/>\n<a href=\"http:\/\/blog.austinkids.org\/2010\/\" target=\"_blank\" rel=\"noopener noreferrer\"> http:\/\/blog.austinkids.org\/2010\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u00cen 2011, am avut ocazia s\u0103 particip la o activitate de formare printr-un grant Comenius-LLP. Cursul a avut loc la Cheltenham-Anglia, unde se desf\u0103\u0219ura un festival al \u0219tiin\u021belor. Mi s-a oferit oportunitatea de a vizita c\u00e2teva \u0219coli \u0219i de a &hellip; <a href=\"https:\/\/iteach.ro\/experientedidactice\/experimentul-biologic-sau-stiinta-in-propria-bucatarie\">Cite\u0219te continuarea <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":1472,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[985],"tags":[163],"class_list":["post-1461","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-erasmus","tag-corina-kodjabashija"],"_links":{"self":[{"href":"https:\/\/iteach.ro\/experientedidactice\/wp-json\/wp\/v2\/posts\/1461","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/iteach.ro\/experientedidactice\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/iteach.ro\/experientedidactice\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/iteach.ro\/experientedidactice\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/iteach.ro\/experientedidactice\/wp-json\/wp\/v2\/comments?post=1461"}],"version-history":[{"count":15,"href":"https:\/\/iteach.ro\/experientedidactice\/wp-json\/wp\/v2\/posts\/1461\/revisions"}],"predecessor-version":[{"id":8952,"href":"https:\/\/iteach.ro\/experientedidactice\/wp-json\/wp\/v2\/posts\/1461\/revisions\/8952"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/iteach.ro\/experientedidactice\/wp-json\/wp\/v2\/media\/1472"}],"wp:attachment":[{"href":"https:\/\/iteach.ro\/experientedidactice\/wp-json\/wp\/v2\/media?parent=1461"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/iteach.ro\/experientedidactice\/wp-json\/wp\/v2\/categories?post=1461"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/iteach.ro\/experientedidactice\/wp-json\/wp\/v2\/tags?post=1461"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}