BIOLOGY 101 EXAM 1 UNC QUESTION WITH CORRECT ANSWERS 2026

BIOLOGY 101 EXAM 1 UNC QUESTION
WITH CORRECT ANSWERS 2026
Moleculesl-lCORRECTlANSWERSl-
Almoleculelislalgrouploflatomslheldltogetherlbylchemicallbondslthatlstorelpotentiallenergy.



Almoleculelislformedlbyl2ltolseveralldozensloflatoms



Somelmoleculeslhavellargelamountsloflpotentiallenergyl(PF)linltheirlchemicallbonds,ltheylservelasl"
EnergylMolecules"lthatlprovidelkineticlenergylforlalllcelllactivitieslwhenltheirlchemicallbondslarelbr
oken.



AdenosinelTriphosphatel(ATP)l-lCORRECTlANSWERSl-
Islaluniversallenergylmoleculelfoundlinlalmostlallllivinglorganisms



Macromoleculel-lCORRECTlANSWERSl-
Almacromoleculelislformedlbylhundredslorlthousandsloflatoms



Chemicallbonding's:lIoniclBondsl-lCORRECTlANSWERSl-
Formedlbylatomslbeinglattractedltoleachlotherldueltoloppositelelectricallcharges.

•lAlcationl(positivelcharge)landlanlanionl(negativelcharge)larelusuallylinvolvedlinlioniclbonds.

(e.g.lNa++lCl-→lNaCl).



ChemicallBonding's:lCovalentlbondsl-lCORRECTlANSWERSl-
Formedlbylthelsharingloflelectronslbetweenl2latomsl(e.g.lH2O).

•lAtomslthatlformlcovalentlbondslnotlonlylgainlextralpotentiallenergy,ltheylbecomelmorelstablelbec
auseloflmorelelectronslonlouterlorbits.

•lStrongestltypeloflchemicallbondinglinlbiologicallmolecules

,•lAllowinglcellsltolbuildllargerlmoleculeslandlmacromolecules.



*Verylstronglbond;lveryldifficultltolbreaklbutloncelbrokenlitlreleasesllotsloflenergy.



Electronegativityl-lCORRECTlANSWERSl-Thelattractionloflanlatomlforlshared

electrons.l

IflthelatomslinlalmoleculelhavelSIMILARlelectronegativity,lthelelectronslremainlequallylstoredlbetw
eenl2lnucleilandlthelcovalentlbondlislsaidltolbelNON-POLAR.l

Iflonelelementlislmorelelectronegative,litlpullslthelsharedlelectronslcloserltolitself,

creatinglPOLARlcovalentlbond.



ChemicallBonding's:lHydrogenlBondsl-lCORRECTlANSWERSl-
Weakestlchemicallbond;lbutlverylimportantlbclitlplayslalkeylrolelinlforminglinternallshapinglandlfoldi
nglofllargerlmolecules.;lcanlbreaklandlbelremadelagain.

•lHydrogenlatomslcontainlonlyl1lprotonlandl1lelectron,laslalresultlwhenlitlislsharinglitslelectronlwithl
anotherlatom,litlhaslalpartial

positivelchargel(i.e.lH+).

•lH+ltendsltolbelattractedltolthelpartiallnegativelchargelofloxygenl(O-)landlnitrogenl(N-
),lforminglhydrogenlbonds.



Importantlpropertiesloflwaterl(H2O):lHighlpolarityl-lCORRECTlANSWERSl-
Partiallelectricallchargeslofloxygenland

hydrogenlatomslinlwaterlmoleculeslcauselpolarity,lallowinglwaterltolinteractlwithlionslandlotherlpol
arlmolecules.



Importantlpropertiesloflwaterl(H2O):lHeatlStoragel-lCORRECTlANSWERSl-
Hydrogenlbondslformedlbetweenlwater

moleculeslcanlabsorblheatlwhenltheylbreakl(releaselheatlwhenltheylarelformed),lminimizingltempe
raturelchangeslin

, livinglorganisms.



Importantlpropertiesloflwaterl(H2O):lHighlHeatloflVaporizationl-lCORRECTlANSWERSl-
Itltakeslallotloflenergyltolbreaklmanylhydrogenlbondslinlwaterlbeforelevaporationlislpossible.



Importantlpropertiesloflwaterl(H2O):lLowldensityloflIcel-lCORRECTlANSWERSl-
Inlcoldltemperature,lhydrogenlbonds

inlwaterlspreadlfartherlapart,lforminglicelcrystallwhichlisllessldenselthanlliquidlwater,landlaslalresultli
celcanlfloatlonlwater.

Thislpreventslfreezinglofllakes.



Importantlpropertiesloflwaterl(H2O):lCohesionl-lCORRECTlANSWERSl-
Hydrogenlbondslholdlwaterlmoleculesltogether,lwhichlallowslwaterltolbeltransportedlupwardlinlthe
lvascularlsystemloflplants.




WaterlaslalPowerfullSolventl-lCORRECTlANSWERSl-Ionslandlpolarlmoleculeslare

attractedltolthelpartiallchargesloflwaterlmolecules,lallowingltheselmoleculesltolbeldissolvedlinlwate
rlandlfromlnewlchemical

behavior.



WaterlOrganizeslNonpolarlMoleculesl-lCORRECTlANSWERSl-
Moleculeslthatlarelnonpolarl(i.e.lfatlorloil)l"doeslnotldissolve)larelnotlwater-
soluble,laslalresultlwilllbelcrowdedltogetherlandlfromltheirlownlinteraction.



Waterlionizesl-lCORRECTlANSWERSl-
WhenlcovalentlbondsloflalwaterlmoleculelbreaklSpontaneously,litldissociateslintolH+landlOH-
lalprocesslcalledlionization.lH+(hydrogenlion)lcontributesltolthelacidityloflalsolution,lwhilelOH-


(hydroxidelion)lcontributesltolthelalkalinityl(basic)loflalsolution.