On food and cooking the science and lore of the kitchen ( PDFDrive ) 1531
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thehigherthetemperatureofafoodorpan,
thehotteritis,thefasteritsmoleculesare
movingandcollidingwitheachother.And
simplemovementisthekeytotransforming
moleculesandfoods.Asmoleculesmove
fasterandmoreforcefully,theirmotionsand
collisionsbegintoovercometheelectrical
forcesholdingthemtogether.Thisfreessome
atomstofindnewpartnersandrearrange
themselvesinnewmolecules.Heatthus
encourageschemicalreactionsandchemical
change.
BondEnergy
Thesecondkindofenergythat’simportantin
thekitchenistheenergyofthechemical
bondsthatholdmoleculestogether.Whentwo
ormoreatomsbecomeamoleculebysharing
electronsandbondingwitheachother,they’re
pulledtogetherbyanelectricalforce.Soin
theprocessofformingthebond,someoftheir
electricalenergyistransformedintoenergyof
motion.Andthestrongertheelectricalforce,
themorerapidlytheyacceleratetowardeach
other.Thestrongerthebond,themoreenergy
isreleased—lost—fromthemoleculeinthe
formofmotion.Strongbonds,then,“contain”
lessenergythanweakbonds.Thisisanother
wayofsayingthattheyaremorestable,less
susceptibletochange,thanweakbonds.
Van der Waals bonds. Thanks to fluctuations
inthepositionsoftheirsharedelectrons,even
the nonpolar chains of carbon and hydrogen
atoms in fats experience weakly attractive
electricalforces(dottedlines).
Bondstrengthisdefinedastheamountof
energyreleasedfromtheparticipatingatoms
whentheyformthebond.Thisisthesameas
theamountofenergyrequiredtobreakthat
