1 / 20

Energy

Maintenance, growth, reproduction, activity. Energy. Food/fuel is oxidized to form ATP. Metabolism =. Metabolic Rate =. 1. Endothermy vs. Ectothermy. 1. Endothermy vs. Ectothermy. physiological correlates of huge MR difference. Higher SA/V in lungs; complex, efficient heart

barth
Download Presentation

Energy

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Maintenance, growth, reproduction, activity Energy Food/fuel is oxidized to form ATP Metabolism= Metabolic Rate=

  2. 1. Endothermy vs. Ectothermy

  3. 1. Endothermy vs. Ectothermy • physiological correlates of huge MR difference Higher SA/V in lungs; complex, efficient heart Mitochondrial membrane SA ~4-5X bigger Greater enzyme activity

  4. 1. Endothermy vs. Ectothermy

  5. ectotherms endotherms MR MR temperature temperature 2. Temperature affects MR

  6. 3. Hibernation, Estivation, Torpor What factors affect an animal’s metabolic rate? Many animals lower MR well below resting levels

  7. Hibernation/torpor

  8. Body Temperature Daytime temp Time of day Significantly lowered Tb 3. Hibernation/torpor

  9. 4. Activity What factors affect an animal’s metabolic rate?

  10. Golden-mantled ground squirrels: What factors affect an animal’s metabolic rate? 5. Reproductive Status • Humans:MR increases 30% near term -growth of fetus -fetal metabolic requirements -growth of mammary tissue - lactation takes up 1/3 of yearly energy budget!

  11. 1.4 kJ meal 5.6 kJ meal What factors affect an animal’s metabolic rate? 6. Digestion: “specific dynamic action”

  12. What does measuring O2 consumption tell us? Endotherms: Ectotherms: • basic metabolism • basic metabolism • thermoregulation • digestion • digestion • activity • activity • reproduction/growth • reproduction/growth

  13. Fuel + 6O2 6CO2 + 6H2O + 2820 kJ Measuring MR O2 consumption CO2 production food intake (fuel) + + H2O + ATP + heat Complete oxidation of 1 mol glucose: (C6H12O6) • Amount of energy ingested, O2 consumed, or CO2 produced is directly related to amount of heat produced • BUT, heat production varies with foodstuff being oxidized…

  14. Lavoisier & Laplace 79.9 cal melts 1 g ice (335 Joules) Measuring MR = “direct calorimetry”

  15. Measuring O2 consumption: Closed system respirometry: Volume = Initial O2 = Final O2 = (1 hour)

  16. (measuring MR during activity) How can we measure FMR?

  17. BUT, heat production varies with foodstuff being oxidized… Relatively constant, but not exact… HEAT PRODUCTION (KJ) Per gram of food Per liter of O2 consumed Per liter of CO2 produced 21.1 17.1 21.1 carbohydrates 19.8 38.9 27.9 lipids 18.7 17.6 23.3 Proteins (urea)

  18. 18O O H 3H H H (Water) (Doubly-labeled water) How can we measure FMR? Doubly labeled water: • dual isotope technique • can use with free-ranging terrestrial animals • no equipment attached to animal • measures CO2 production

  19. Initial sample 3H isotope in body Final sample 18O time Doubly-labeled water Convert to estimates of CO2 production…

  20. Metabolic Rate Summary • Factors affecting metabolic rate: • Endothermy vs. Ectothermy • Temperature • Hibernation, Estivation, Torpor • Activity • Reproductive Status • Digestion • Starvation • Levels of Metabolism • BMR, SMR, RMR, FMR, PMR, metabolic scope • What is MR and how can you measure it? • Direct Colorimetry (heat production) • Food Consumption • Oxygen Consumption • Carbon Dioxide Production • Field metabolic rate O2 consumption CO2 production food intake (fuel) + + H2O + ATP + heat

More Related