Lesson5.pdf

SCI260–IntroductiontoBiochemistryLesson5Inthisweek’sclass,wediscussedgluconeogenesis,glycogenmetabolism,andthepentosephosphatepathwayandtheirrolesinglucosemetabolism.BasedonthetopicsdiscussedinLecture#5,pleaseanswereachofthefollowingquestions.

1. Whichenzyme-catalyzedreactionsaresharedbetweenthegluconeogenesisandglycolysispathways?(Note:justprovidethenameoftheenzymethatcatalyzeseachofthesharedreactions).

2. Whyaresomeenzymesneededonlyinthegluconeogenesispathwayandnotintheglycolysispathway?

3. Whichoneofthefollowingreactionsonlyoccursduringgluconeogenesis(i.e.,notduringglycolysis)?

a. 1,3-bisphosphglycerateinto3-phosphoglycerateb. Glucose6-phosphateintofructose6-phosphatec. OxaloacetateintoPhosphoenolpyruvated. PhosphoenolpyruvateintoPyruvate

4. Anincreaseinglucagonlevelscan__________.a. Promotethedegradationofglycogen(i.e.,glycogenolysis)b. Occursduringthefastingstate(starvation)c. Promotesthesynthesisofglycogend. AandB

5. Ahighschoolgirlwhoisself-consciousaboutherappearancehasbeenfastingforseveraldaystofitintoadresssheintentionallyboughtasizetoosmallforaschooldance.Whichofherorgans/tissuesisproducingtheglucosethatisbeingsynthesizedthroughgluconeogenesis?

a. Redbloodcellsb. Musclesc. Liverd. Brain

6. Whydoonlysometissues(e.g.,liver)containtheenzymeglucose-6-phosphatase?

7. Whatarethemainproductsofthepentosephosphatepathway,andhowdoesthecellusethem?

8. HowmanymoleculesofATPareproducedduringthemetabolismofone(1)moleculeofglucosethroughthepentosephosphatepathway?

9. Whichtwo(2)moleculesareproducedduringthepentosephosphatepathwaythatarealsoproducedduringglycolysis?

10. Describetwo(2)specificthingsthatmakeNADHandNADPHdifferentfromeachother(Note:considerthestructuralandbiologicalpropertiesofthetwomolecules).

Youmayuseyourtextbookand/ortheinternettoassistyou.Youwillearn10pointsforcorrectlyansweringeachquestion(maximumpointsearned=100points).