1 - Sciences Physiques

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Physique :
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1.'Modèle'simplifié'du'décollage'
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2.'Étude'plus'réaliste'du'décollage'
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Chimie :!
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Le#lait#est# un# produit#biologique#fragile.#L’homme#a# su#exploiter#la#tendance# qu’ont# ses#composants# à# se# séparer# afin#de# le#
conserver.#Pour#faire#du#beurre,#on#recueille#la#matière#grasse#mais#pour#obtenir#du#fromage#ou#du#yaourt,#on#attend#que#les#
protéines#du#lait#coagulent.#
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L’acide#lactique#est#l’un#des#composants#essentiels#du#lait.#
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Données':'
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- Masse'molaire'de'l’acide'lactique':'M'='90'g.molB1'
- pKa%(acide'lactique/ion'lactate)'='3,9'
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Document'2':'Précipitation'de'la'caséine'
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Document'1':'Fabrication'd’un'yaourt'
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Document'3':'Acidité'et'température'
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Document'4':'Évolution'du'pH'lors'de'la'fabrication'du'yaourt'dans'un'atelier'de'production'industrielle'
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