On food and cooking the science and lore of the kitchen ( PDFDrive ) 1530
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more other molecules than a small water
moleculecan.
Energy
EnergyCausesChange
Theparagraphsdirectlyabovedescribe
variousbondsas“weak”and“strong,”easily
ornotsoeasilyformedandbroken.Theidea
ofbondstrengthisusefulbecausemost
cookingisamatterofthesystematicbreaking
ofcertainchemicalbondsandtheformation
ofothers.Thekeytothebehaviorofchemical
bondsisenergy.ThewordisaGreek
compoundof“in”and“force”or“activity,”
andnowhasasitsstandarddefinition“the
capacityfordoingwork,”or“theexertionofa
forceacrossadistance.”Mostsimply,energy
isthatpropertyofphysicalsystemsthat
makespossiblechange.Asystemwithlittle
energyislargelyunchanging.Conversely,the
moreenergyavailabletoanobject,themore
likelythatobjectistobechanged,orto
changeitssurroundings.Ourkitchensare
organizedaroundthisprinciple.Stovesand
ovenschangethequalitiesoffoodbypouring
heatenergyintoit,whiletherefrigerator
preservesfoodbyremovingheatandthus
slowingdownthechemicalchangesthat
constitutespoilage.
Atomsandmoleculescanabsorborrelease
energyinseveraldifferentforms,twoof
whichareimportantinthekitchen.
TheNatureofHeat:MolecularMovement
Onekindofenergyistheenergyofmotion,or
kineticenergy.Atomsandmoleculescan
movefromoneplacetoanother;orspinin
place,orvibrate,andallofthesechangesin
positionororientationrequireenergy.Heatis
amanifestationofamaterial’skineticenergy,
andtemperatureisameasureofthatenergy:
