1. Lab #10 part B In order for chemical reactions to occur: Molecules must collide - They collide w/ a certain impact

2. In order for chemical reactions to occur: The greater their kinetic energy… The greater their force of collision

3. The greater the kinetic energy… the greater the force of collision

4. TEMPERATURE IS A MEASURE OF KINETIC ENERGY!

5. Increase in temperature … leads to an increase in collisions …

6. Living organisms need the proper temperature for proper amount of collisions

7. Living organisms have a temp. dilemma: Must have increased temperature for proper molecular collisions

8. Temperatures too high (about 40 o C or higher) May denature proteins and ultimately kill an individual

9. Evolution has solved this problem: 1) Enzymes

10. Evolution has solved this problem: 2) Behavioral, morphological and physiological traits designed to maintain a warm body…

11. Ectotherm vs. Endotherm Rapid Metabolism produces much heat… Metabolism is soooooo slow, their bodies produce little heat… every animal besides a bird or mammal

12. terrestrial How does a terrestrial ectotherm thermo regulate?

14. What is the ADVANTAGES of ectothermy??? require very little energy… b/c their metabolism is soooo slow. do not have to eat as often. do not have enough energy for sustained exertion.

15. terrestrial How does a terrestrial endotherm thermo regulate? Maximize blood flow Insulating fat, feathers, or fur

16. What is the ADVANTAGES of endothermy??? elevated, constant body temperature, despite changes in environment can live in colder climates... HOWEVER, must have a constant food supply!! maximize metabolic rate.

17. How does an aquatic ectotherm thermoregulate?

18. Their metabolism speeds up or slows down?

19. Circulation quick review Water flows over gills as fish swims Gills are made of thousands of gill filaments Fish, open their mouths, and H 2 O flows over the gills

20. Deoxygenated bloodDeoxygenated blood flows into the gills Oxygen flows from the water into the gills and is picked up by the blood. It goes to the rest of the body. Circulation quick review

21. The effectiveness of gas exchange in some gills, including those of fishes Is increased by ventilation and countercurrent flow of blood and water Countercurrent exchange Figure 42.21 Gill arch Water flow Operculum Gill arch Blood vessel Gill filaments Oxygen-poor blood Oxygen-rich blood Water flow over lamellae showing % O 2 Blood flow through capillaries in lamellae showing % O 2 Lamella 100% 40% 70% 15% 90% 60% 30% 5% O2O2

22. Form fits Function Figure 42.1

23. On with the Lab…

24. The lab examines the relationship between metabolic rate & body temp. in ectotherms

25. We will measure the heart rate (indirectly) to measure metabolism The rate of metabolism in ectothermic animals increases as the environmental temperature increases This rise occurs because the reactants in the cell have greater thermal energy, and many cellular enzymes are more active as temperature increases.

26. What is the effect on a 10 o C rise in temperature? The relationship between temperature changes & metabolic rate is often measured as Q10. If the metabolic rate doubles with a 10°C increase in temperature, then Q10 = 2.

27. What is the effect on a 10 o C rise in temperature? Simply choose two points on the graph that are 10 degrees apart, Determine their respective rates, and find their quotient.

28. What is the effect on a 10 o C rise in temperature? The usefulness of calculating a Q 10 value is that it suggests whether or not the metabolic reactions being examined are controlled by temperature or by some other factor. IF Q10 IS NOT 2 (aprx.) SOMETHING BESIDES TEMP. IS AFFECTING THE RATE!

29. If the Q10 = 3… then for every 10 o C increase in temp / metabolic rate would TRIPLE Q10 measures the increase in metabolic activity resulting from an increase in body temperature.

30. You can measure Q10 indirectly, by measuring heart rate beats min.

31. Q 10 = (higher temp.) Rate at temperature “X” + 10 o C Rate at temperature “X” (lower temp)

32. Q10 is the ratio of the rate of a reaction at one temperature divided by the rate of the same reaction at a temperature 10 C° less. The larger the Q10 the greater the effect the temperature has on the reaction. A value of Q10 = 1 implies temperature has no effect on the reaction.