Lab 3:!Metabolism and Enzymes, Food preservation of dairy products"

Make cheese using the enzyme chymosin (in rennet)" Compare to use of an acidic liquid (vinegar)"

Biological molecules and enzymes"Effects of environment on chemical reactions"

Make yogurt (or kefir) to use the metabolism of microorganisms to preserve dairy products"

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Marin County is Famous for

Milk Production;

How to preserve it?"

Sonoma/Marin cheese trail"http://cheesetrail.org/trail-map/"

CA Cheese Trail"“Happy Cows” campaign for CA milk"

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Enzymes, Chemistry, & Metabolism"Scientific method, measurements, graphing"Enzymes and biological molecules"Chemistry for biology""

ByThomasShafee(Ownwork)[CCBY-SA4.0(hAp://creaEvecommons.org/licenses/by-sa/4.0)],viaWikimediaCommons

SUBSTRATES

PRODUCT

REACTION ENZYME

CATALYZE

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Enzymes, Chemistry, & Metabolism"Enzymes and biological molecules"Metabolism (lacto-fermentation)"Chemistry for biology""

ByThomasShafee(Ownwork)[CCBY-SA4.0(hAp://creaEvecommons.org/licenses/by-sa/4.0)],viaWikimediaCommons

DENATUREHYDROPHILIC

HYDROPHOBICACIDIC

BASIC

pH

DavidTJones,UniversityCollege,LondonhAp://www0.cs.ucl.ac.uk/staff/d.jones/t42morph.html8/11/16 4

How does rennet curdle milk to make cheese? What about using acid?"

Micelles of casein (protein) and fat expose hydrophilic molecules to water in milk

solution/suspension"Chymosin acts on kappa-casein, micelles now

hydrophobic and clump together"Albumin in egg denature when cooked"

Extreme pH also denatures proteins""

hAp://biotechlearn.org.nz/focus_stories/cheesemaking/the_science_of_cheeseFood-Info.net/Food-InfoFoundaEon,WageningenUniversity

ByRMADLA(Ownwork)[CCBY-SA3.0(hAp://creaEvecommons.org/licenses/by-sa/3.0)],viaWikimediaCommons8/11/16 5

Kefir Demonstration!"Lacto fermentation creates an acidic environment"

Acid denatures casein, curdles milk"Low pH also prevents spoilage"

Yogurt, kefir, kishk, tara, buttermilk"Kefir contains yeast, multiple organisms - makes

‘grains”""

KEFIRPROTOCOL•  200mLWholeMilk•  15mLKefirstarter•  Roomtemp•  Swirlwhenremember•  Checkin24-48h

LifewayOrganicKefircontains:B.lac's,Lb.lac's,S.floren'nus,S.diacetylac-s,Lb.acidopilis,B.bacterialongum,Lb.case,Lb.reuteri,Lb.plantarum,Lb.rhamnosus,B.bacteriumbreve,Leuconostoccremoris

BrownCowPlainCreamtopYogurtcontains:S.thermopiles,L.bulgaricus,L.acidophilius,Bifidus

hAps://en.wikipedia.org/wiki/KefirByA.Kniesel(FotografiertvonA.Kniesel)[GFDL(hAp://www.gnu.org/copyleb/fdl.html)orCC-BY-SA-3.0(hAp://creaEvecommons.org/licenses/by-sa/3.0/)],viaWikimediaCommons

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