370 likes | 806 Vues
3.3. NUTRITION AND ENERGY SYSTEMS. IB SEHS. Starter. What distinguishes animal cells versus plant cells ? Where does respiration occur ?. Learning Objectives. Everyone will be able to Identify the different parts of the mitochondrion. 2. Define and understand respiration
E N D
Starter • Whatdistinguishes animal cells versus plantcells? • Wheredoesrespirationoccur?
Learning Objectives Everyone will be able to • Identify the different parts of the mitochondrion. 2. Define and understand respiration 3. Explain the loss and gain of phosphate in an adenosine molecule
Mitochondrion Ultrastructure • Energyprovision • Onlysitewhereoxygenisused • Location: Allcells, butred cells • Ultrastructureshownright
The Energy currency, ATP • ATPistheenergycurrency • AdenosineTriPhosphateis a moleculecreatedfrombiochemicalenergyin organicmoleculesbycatabolicreactions.
Cell Respiration • Cellrespirationisthecontrolledrelease of energy in theform of ATPfromorganiccompounds in cells
Energy metabolism: ATP • ATPconnectsanabolic and catabolicreactions. • Ingestedfoodstored as fatsorglycogen Catabolism ATP Energy
ATP role in muscle contraction • Actin and myosin use ATP to drive contraction • MusclefibershavesufficientATP foronly 2 seconds of contraction. Therest comes fromcatabolicreactionsthatgenerate ATP • ATP + H2O ADP + P + Energy Contraction
Anaerobic Energy Systems Creatine Phosphate System • CreatinePhosphateSystem CP isanotherhighenergymolecule BUT cannot be useddirectly. It´s a checkweneed to first cash intoATP. • Duringexercise, afterspendingour 2 secworth of ATP, CP helps re-synthesizing ATP, givingenergyfor up to first 20 secto muscles
Creatine Phosphate System goes both ways • The ATP-CP system can gobothways. • Duringexercise, first 20 sec, ATP is re-synthesized • At rest, ATP can be used to refillour store of PCr in themuscle REST<------>EXERCISE
Anaerobic Energy Systems Lactic Acid System • AnaerobicGlycolysisLOCATION: CYTOPLASMof allcells Glucose ATP + pyruvate • Limitedsupply of oxygenormithocondrialeads to Pyruvate Lactate + 2 ATP • LacticAcidSystemisquickand ideal of hardexercise
Anaerobic Energy Systems Lactic Acid System • IstheLacticAcidSysteman ideal systemforanelongatedperiod of hardexercise? • Interpret and commentonthefollowinggraph
Aerobic Energy Systems • Location:MITOCHONDRIA • Electrontransportchain in theinnermembrane • Krebs Cyclein thematrix • β-oxydationin thematrix
Aerobic Energy Systems • GlucoseOxydation • Pyruvate acetil CoAKrebsCycle in thematrix • H+ ionsreleased ELECTRON TRASPORT CHAIN ENERGY AS ATP
Aerobic Energy Systems • FatOxydation • Free fattyacidsenterthematrix β-oxydationAcetil CoA Krebs Cycle H+ Electrontransportchain Energy as ATP • FatCANNOT BE USED ANAEROBICALLY, unlikeglycogen
STARTER • Discuss in pairswhatisthedetermiant factor forcells to use oneenergysystemoranother. Explain in detail.
THE BIG QUESTION • Howdoestheelenctrontranportchainhelpthecellsynthesizing ATP? • https://www.youtube.com/watch?v=Ak17BWJ3bLg
INDIVIDUAL ACTIVITY • YOU HAVE RECEIVED A MUSCLE CELL (LONG WHITE PAPER) • DRAW A DIAGRAM, INCLUDING CELL MEMBRANE, CYTOSOL AND MITHOCONDRION WITH DETAIL, IN WHICH THE THREE METABOLIC PATHS ARE SHOWN: ANAEROBIC LACTIC ACID, GLUCOSE AND FATTY ACID OXYDATION. INCLUDE MAIN REACTIONS ONLY • BE READY TO EXPLAIN YOUR CELL.
Oxygen Deficit and Excess Post-Exercise Oxygen Consumption (EPOC) • Start of exerciseOxygenneed > oxygensupply: O2 DEFICIT ATP, PCr and anaerobicglycolysisactivatequicker! • Afterexercise Oxygensupplygreaterthanneeded: EPOC orO2DEBT offset consequences of anaerobicmetabolism, repair of tissue, myoglobinoxydation, etc.
Oxygen Deficit and Excess Post-Exercise Oxygen Consumption (EPOC) • Analyze and commentonthefollowinggraph:
Contribution of the Energy Systems during exercise • High intensityexercise highrate of ATP needed Fastmetabolism PCr (20 sec) and LacticAcidSystem • Longer & Slowerexercise Aerobic metabolism: Glucose and Fatoxydation (slowestone) • Glucose (anaerobic and aerobic) metabolismiskeyacrossallintensities of exercise.