SCI260–IntroductiontoBiochemistryLesson6
1. Describe(inwords)theoverallstructureofalipidbilayer.
2. Whataretheproperties(i.e.,characteristics)ofthelipidbilayerofacellthatmakeitimpermeabletoionsandmostmolecules?
3. Describetheroleofcholesterolinmaintainingthefluidityofthelipidbilayerofa
cell?
4. Thetriglyceridesinanimalstendtobesolids(i.e.,fats)atroomtemperaturewhereasthetriglyceridesinplantstendtobeliquids(i.e.,oils)atroomtemperature.Basedonthisfact,whatcanyouconcludeaboutthecharacteristicsofthefattyacidsinanimaltriglyceridescomparedtothefattyacidsinplanttriglycerides?
5. Peanutoilcontainsahighpercentageofmonounsaturatedtriglycerideswhereas
vegetableoilcontainsahigherpercentageofpolyunsaturatedtriacylglycerols.Abottleofpeanutoilandabottleofvegetableoilarestoredinapantrywithanoutsidewall.Duringacoldspell,thepeanutoilfreezes,butthevegetableoilremainsliquid.Explainwhy.
6. HowmanymoleculesofATParegeneratedwhenstearicacid(i.e.,stearate),an
18-carbonsaturatedfattyacid,iscompletelyoxidizedviathebeta-oxidationpathwayinthemitochondria?a) 112b) 129c) 146d) 163
7. Whichofthefollowingfattyacidsbelowareessentialforhumans?*Selectoneor
more.a) Oleicacidb) Linoleicacidc) Linolenicacidd) Palmitoleicacide) Eicosapentaenoicacid(EPA)
8. RefertoQuestion7,lookupthestructuresofeachfattyacidthatisessentialandexplainwhytheyareessentialforhumans?
9. Aretransfattyacidssaturatedorunsaturated?
10. Providefour(4)examplesoffoodsthatcontaintransfattyacids.Youmayuseyourtextbookand/ortheinternettoassistyou.Youwillearn10pointsforcorrectlyansweringeachquestion(maximumpointsearned=100points).