Enzymatic Regulation of Zooplankton Respiration

4th 4th International International Zooplankton Zooplankton Production Symposium Production Symposium, Hiroshima, , Hiroshima, Japan Japan May 2007 May 2007 Enzymatic Regulation of Zooplankton Respiration *T. T. *T. T. Packard Packard & **M. G & **M. Gó ómez mez *Marine Science Institute, Barcelona, Spain *Bigelow Laboratory for Ocean Sciences, USA **Marine Science Faculty, Universidad de Las Palmas de Gran Canaria, SPAIN QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. ULPGC ULPGC BLO S Metabolic Theory of Ecology Metabolic Theory of Ecology by Brown et al. by Brown et al. Ecology ( Ecology (2004) ;85:1771 2004) ;85:1771- -1 1789. 789.  Based on metabolism ( Based on metabolism (Klieber Klieber’ ’s s Law Law), but ), but applied to growth, to development time, to applied to growth, to development time, to the ocean, & to many other biological the ocean, & to many other biological phenomenon. phenomenon.  Philosophy: Supply Philosophy: Supply- -side Economics side Economics* *  R = F(Metabolic Distribution Networks) R = F(Metabolic Distribution Networks)  R = Delivery rate of these fractal networks R = Delivery rate of these fractal networks Metabolic Theory of Ecology Metabolic Theory of Ecology by Brown et al. by Brown et al. Ecology ( Ecology (2004) ;85:1771 2004) ;85:1771- -1 1789. 789. R = KoM3/4e-Ea/kT  Part A: Part A: Nutrient Nutrient dependency dependency [ [reactants reactants] ]  Part B: Part B: Biomass Biomass dependency ( dependency (Kleiber Kleiber’ ’s s Law) Law) [ [reactant fluxes, reaction rates reactant fluxes, reaction rates] ]  Part C: Part C: Temperature Temperature dependency dependency ( (Boltzmann Boltzmann Factor) [ Factor) [system kinetic energy system kinetic energy] ] Why Kleiber’s Law is correct. Zooplankton R & Zooplankton R & Φ Φobey obey Kleiber Kleiber’ ’s s Law Law Kleiber's Law (Zooplankton, 5 phyla) y = 0,7565x + 0,1757 R2 = 0,9363 -3 -2 -1 0 1 2 3 -3 -2 -1 0 1 2 3 Log (Dry Weight ) R = 1.5W0,76 Kleiber's Law (Zooplankton, 5 phyla) y = 0,7913x + 0,5155 R2 = 0,9458 -3 -2 -1 0 1 2 3 -3 -2 -1 0 1 2 3 Φ = 3.3W0,79 Log (Dry Weight) Why the Why the MTE MTE is right. is right. R = f(M + T) R = f(M + T) Biomass, Respiration and Nutrient as f (time) 0 50 100 150 200 250 300 350 0 5 10 15 20 25 30 TIME (hours) Pyruvate (x15), Protein, & R QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Why Why Kleiber Kleiber’ ’s s Law and the Law and the MTE MTE are wrong. are wrong. Cell Protein Respiration Nutrient The MTE & Kleiber’s Law can’t predict respiration under nutrient limitating Conditions. R = KoM3/4e-Ea/kT R = SΦA(e -Ea/RT )/(Kβ+ S) Our alternative is based on the recognition: 1. That the electron transport system (ETS) controls respiration and is a measure of potential respiration (Φ). 2. that mitochondrial NADH (and NADPH) control the activity of the ETS. 3. and that Michaelis-Menten kinetics describes the impact of substrate (reactant) limitation on reaction rates. Ae-Ea/RT R = SΦA(e -Ea/RT )/(Kβ+ S) In addition, we can build on 100 years of research by recognizing the Arrhenius equation’s efficiency in describing the temperature dependence of biological as well as chemical rate processes. Note! Ais necessary! A counter proposal: A First Principle Respiration Model* A counter proposal: A First Principle Respiration Model* R = SΦA(e -Ea/RT )/(Kβ+ S)  Based on: Based on: respiratory potential respiratory potential ( (Φ Φ) as set by ) as set by the respiratory electron transport system. the respiratory electron transport system.  Philosophy: Demand Philosophy: Demand- -side side Economics Economics* *  R = f(Cellular Demand for ATP) R = f(Cellular Demand for ATP)  R = Delivery rate of R = Delivery rate of e e- -to to Cyt Cyt a a- -a a3 3 R = SΦΑ(e-Ea/RT )/(Kβ+ S) 0 25 50 0,00 10,00 20,00 30,00 TIME (hours) RESPIRATION (Predicted & Measured) Measured Modeled QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. A First Principle Model for Respiration A First Principle Model for Respiration R = f (T). Use the Arrhenius Equation, it incorporates the Boltzmann Factor! R = SΦΑ(e-Ea/RT )/(Kβ+ S) Zooplankton bathipelagic Zooplankton bathipelagic Temp (ºC) 1/Temp X 103 (ºK) POTENTIAL RESPIRATION ( nl O2 h-1 l-1). LOG e (POTENTI AL RESPIRATION). 16 16 0.20 0.40 0.60 0.80 1.00 1.20 0.00 -4.00 -3.20 -2.40 -1.60 -0.80 0.00 -4.60 0 15 30 45 60 3.0 3.2 3.4 3.6 3.8 Φ= Ae-Ea/RT Slope = -Ea/R Ea = 13.2 kcal/mol CONCLUSION CONCLUSION  The The MTE MTE and and Kleiber Kleiber’ ’s s Law alone can not predict or Law alone can not predict or explain respiration on the small scale. explain respiration on the small scale.  Potential respiration, substrate depletion, and Potential respiration, substrate depletion, and Michaelis Michaelis- -Menten kinetics can explain and predict Menten kinetics can explain and predict respiration on the respiration on the small scale. small scale. For all their help, support, and encouragement we thank Santiago TorresCurbelo and Miguel Alcaraz. ULPGC ULPGC QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. ACKNOWLEDGEMENTS ACKNOWLEDGEMENTS BLO S ULPGC ULPGC QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Thanks for your attention Thanks for your attention. . BLO S