Chapter 40: Animal Form and Function NEW AIM: Body Systems of complex animals emphasizing surface area required to perform nutrient absorption, gas exchange and excretion.

Chapter 40: Animal Form and Function NEW AIM: Reminder of the fate of ingested organic molecules and their electron’s ability to accelerate (energy) within animals (heterotrophs). Cellular Respiration Biosynthesis (endergonicusing ATP) - Energy transferred to ATP (60% lost to IR/heat) - Exergonic (-ΔG) - Making the molecules you need from the organics you eat (protein synthesis, amino acid synthesis, fatty acid synthesis, etc…) - Endergonic (+ΔG) - Need the ATP to make this happen (energy couping)

Chapter 40: Animal Form and Function NEW AIM: Bioenergetics Metabolic Rate? The sum of all the energy requiring biochemical reactions…how much energy you use! How is metabolic Rate Measured? - One can measure how much O 2 the animal consumes (ex. O 2 per gram per hour) or CO 2 produced (both a measure off how much cell respiration is going on). (look at the figure to the right…)

Chapter 40: Animal Form and Function NEW AIM: Bioenergetics Metabolic Rate? Figure - Respirometer used to measure metabolic rate of fish from Southern California. How is metabolic Rate Measured? - One can measure how much O 2 the animal consumes (ex. O 2 per gram per hour) or CO 2 produced (both a measure off how much cell respiration is going on). (look at the figure to the right…) - This can be achieved using a respirometer

Chapter 40: Animal Form and Function NEW AIM: Bioenergetics - This is a respirometer used in an AP Biology Lab where one measure the metabolic rate of a grasshopper, peas or anything else you like. - As the grasshopper uses O 2 for cell resp the air volume in the pipette will decrease allowing you to measure O 2 consumption. Wait, what about the CO 2 ? What is the role of KOH in the experimental setup? What is the role of the glass beads in the pea respirometer setup? KOH reacts with CO 2 to form a solid (K 2 CO 3 ). Otherwise as O 2 was used, CO 2 would be produced and no volume change would occur. The glass beads are act as a negative control and have the same volume as the peas. What is a negative control? A group in which no response is expected. What if we see volume change in the negative control? What does this mean? Perhaps the temperature of the water has changed caused the gas to expand/contract (PV=nRT). We would need to adjust the experimental group accordingly.

Chapter 40: Animal Form and Function NEW AIM: Bioenergetics What if we see volume change in the negative control? What does this mean? Perhaps the temperature of the water has changed caused the gas to expand/contract (PV=nRT). We would need to adjust the experimental group accordingly. Question – the pea respirometer shows a 3ml decrease in gas volume. However, the glass beads (neg. control) show a 1ml decrease. How would you proceed with data analysis? You would need to subtract the 1ml from the 3ml because the pea respirometer is in the same environment and 1 of those 3 mls has nothing to do with respiration…

Chapter 40: Animal Form and Function NEW AIM: Bioenergetics Metabolic Rate? The sum of all the energy requiring biochemical reactions…how much energy you use! How is metabolic Rate Measured? - One can also use a calorimeter (device that measures how much heat you give off). (look at the figure to the right…)

Chapter 40: Animal Form and Function NEW AIM: Bioenergetic Strategies Endothermic strategy -Body is warmed by metabolism to a steady internal temperature regardless of external temperatures. - Obtain heat from external sources mainly – body temp changes with external temp - Warm-blooded - Generally have a higher metabolic rate compared to ectotherms. Ectothermic strategy - Cold-blooded - Birds and mammals…convergent evolution example! - Lower metabolic rate - Everything other than birds and mammals like reptile, amphibians, fish, etc…

Chapter 40: Animal Form and Function NEW AIM: Bioenergetic Strategies Endothermic strategy Basal Metabolic Rate - Metabolic rate of an ectotherm at rest - Metabolic rate of an endotherm at rest Ectothermic strategy Standard Metabolic Rate - Varies with external temperature - Stable due to consistent internal temps - Enzymes always running at there optimum to 1800 kcal per day for humans

Chapter 40: Animal Form and Function NEW AIM: Energy Expenditure Notice that humans have a very high basal metabolic rate…why? Endotherms Ectotherm Annual energy expenditure (kcal/yr) 800,000 Basal metabolic rate Reproduction Temperature regulation costs Growth Activity costs 60-kg female human from temperate climate Total annual energy expenditures (a) 340,000 4-kg male Adélie penguin from Antarctica (brooding) 4, kg female deer mouse from temperate North America 8,000 4-kg female python from Australia Energy expenditure per unit mass (kcal/kgday) 438 Deer mouse 233 Adélie penguin 36.5 Human 5.5 Python Energy expenditures per unit mass (kcal/kgday) (b) Animals have evolved to spend their daily energy allotment in different ways… We are large endotherms Why do penguins have large activity costs? They must hunt for their food…fish. This isn’t free. Penguins have crazy low temperature costs for a species that tends to live in cold places…?? Evolutionary adaptations – a lot of blubber (triglycerides/insulation) under thick skin

Chapter 40: Animal Form and Function NEW AIM: Energy Expenditure Why do mice have such high temp expenditures? Endotherms Ectotherm Annual energy expenditure (kcal/yr) 800,000 Basal metabolic rate Reproduction Temperature regulation costs Growth Activity costs 60-kg female human from temperate climate Total annual energy expenditures (a) 340,000 4-kg male Adélie penguin from Antarctica (brooding) 4, kg female deer mouse from temperate North America 8,000 4-kg female python from Australia Energy expenditure per unit mass (kcal/kgday) 438 Deer mouse 233 Adélie penguin 36.5 Human 5.5 Python Energy expenditures per unit mass (kcal/kgday) (b) Animals have evolved to spend their daily energy allotment in different ways… They are sooo small. This means a large surface area to volume ratio. All that surface means a lot of heat loss. Notice the snakes…no energy spent on temp expenditure…why? Its an ectotherm

Chapter 40: Animal Form and Function NEW AIM: Energy Expenditure Notice who wins per unit mass… Endotherms Ectotherm Annual energy expenditure (kcal/yr) 800,000 Basal metabolic rate Reproduction Temperature regulation costs Growth Activity costs 60-kg female human from temperate climate Total annual energy expenditures (a) 340,000 4-kg male Adélie penguin from Antarctica (brooding) 4, kg female deer mouse from temperate North America 8,000 4-kg female python from Australia Energy expenditure per unit mass (kcal/kgday) 438 Deer mouse 233 Adélie penguin 36.5 Human 5.5 Python Energy expenditures per unit mass (kcal/kgday) (b) Animals have evolved to spend their daily energy allotment in different ways… The ectotherms…we burn a lot of fuel keeping warm! Look at the endotherm per unit mass expenditure…do you see a pattern? Look at the next slide as well…

Chapter 40: Animal Form and Function NEW AIM: What trend do you notice concerning metabolic rate of endothermic mammals looking at the figure to the right? The larger the mammal, the lower the metabolic rate PER UNIT MASS. We obviously have a greater basal metabolic rate. Therefore, metabolic rate is inversely proportional to size in animals. In this regard is pays to be large to not lose so much heat (lower surface area to volume ratio). Energy Expenditure

Chapter 40: Animal Form and Function NEW AIM: Countercurrent Heat Exchange Adaptations to lower heat loss Try and figure out the concept displayed by the figure to the right…red can be a hot fluid and blue is a cold fluid. Countercurrent flow is more effective at transferring some property from one fluid to another like heat...because you maintain a steep gradient all the way.

Chapter 40: Animal Form and Function NEW AIM: Vasoconstriction / Vasodilation Adaptations to lower heat loss By controlling smooth muscle wrapping our arterioles (small arteries) near the surface of our bodies, we can regulate heat loss.

Chapter 40: Animal Form and Function NEW AIM: Countercurrent Heat Exchange in animals Adaptations to lower heat loss In the flippers of a dolphin, each artery is surrounded by several veins in a countercurrent arrangement, allowing efficient heat exchange between arterial and venous blood. Canada goose Artery Vein 35°C Blood flow Vein Artery 30º 20º 10º 33° 27º 18º 9º Pacific bottlenose dolphin Arteries carrying warm blood down the legs of a goose or the flippers of a dolphin are in close contact with veins conveying cool blood in the opposite direction, back toward the trunk of the body. This arrangement facilitates heat transfer from arteries to veins (black arrows) along the entire length of the blood vessels. 1 Near the end of the leg or flipper, where arterial blood has been cooled to far below the animal’s core temperature, the artery can still transfer heat to the even colder blood of an adjacent vein. The venous blood continues to absorb heat as it passes warmer and warmer arterial blood traveling in the opposite direction. 2 As the venous blood approaches the center of the body, it is almost as warm as the body core, minimizing the heat lost as a result of supplying blood to body parts immersed in cold water. 3 Notice how the warm blood moving to the extremities will run countercurrent to the returning arteries to transfer heat efficiently to the blood heading back to the body.

Chapter 40: Animal Form and Function NEW AIM: The process in which an organism adjusts itself to gradual changes in the environment to maintain optimum performance across a range of conditions. Acclimatization 1. Alter amount of insulation (increase subcutaneous fat) 2. Alter metabolic rates (hypothalmus / thyroid story) 3. Alter gene expression Ex. Gets cold…turn off gene for enzyme that works best at warmer temps and turn on a different gene coding for the same enzyme that works best at cooler temps...that is awesome!! 4. Antifreeze in cells EX) Antifreeze proteins (AFPs…yes, this is a thing) – they bind small ice crystals and inhibit their growth!!! Literally they stop ice from forming!!!!!

Chapter 40: Animal Form and Function NEW AIM: AFP from the spruce budworm (Choristoneura fumiferana)…what secondary element is not present in this protein? Acclimatization

Chapter 40: Animal Form and Function NEW AIM: The process in which an organism adjusts itself to gradual changes in the environment to maintain optimum performance across a range of conditions. Acclimatization 1. Alter amount of insulation (increase subcutaneous fat) 2. Alter metabolic rates (hypothalmus / thyroid story) 3. Alter gene expression Ex. Gets cold…turn off gene for enzyme that works best at warmer temps and turn on a different gene coding for the same enzyme that works best at cooler temps...that is awesome!! 4. Antifreeze in cells EX) Antifreeze proteins (AFPs…yes, this is a thing) – they bind small ice crystals and inhibit their growth!!! Literally they stop ice from forming!!!!! 5. Heat-shock Proteins - Proteins made by cells under stressful conditions. This is a group of many different types of proteins. Many act as chaperones that help proteins to fold into their proper tertiary (3-D) structures.

Chapter 40: Animal Form and Function NEW AIM: Energy conservation Torpor Examples 1. Hibernation - Any state of lowered activity, decreased metabolism 2. Estivation Summer torpor – usually to avoid dessication (drying out) 3. Daily Torpor Sleep!! Controlled by biological clocks (circadian rhythms – pineal gland / melatonin) Long term torpor to avoid cold and scarce food

Chapter 40: Animal Form and Function NEW AIM: Energy conservation Torpor This figure shows energy saving of a hibernating mammal. It also indicates that the mammal must arouse periodically through hibernation. The precise reason for the arousal cycle is unknown but hypothesized to be required for routine repair of organs that cannot occur otherwise. Try and figure out what this figure is conveying…

Chapter 40: Animal Form and Function NEW AIM: Temperature Coefficient (Q 10 ) Q 10 is the factor by which the rate of a process changes when the temperature is raised by 10°C. From the AP Biology Reference Table WHAT IS Q 10 ?? For example…what would be the Q 10 for the heart rate of a water flea if the heart rate at 15°C is 50 per minute and at 25°C is 250 per minute? Q 10 = 5 because the rate went up 5X in 10°C

Chapter 40: Animal Form and Function NEW AIM: Temperature Coefficient (Q 10 ) Determine the Q 10 for the heart rate of a water flea if the heart rate at 10°C is 50 per minute and at 30°C is 300 per minute? For this problem we use the formula… Q 10 = (19/16) (10/(21-17)) Q 10 = (1.18) (2.5) Q 10 = 1.51 or the rate increase 1.5X over 10 degrees C Q 10 = (300/50) (10/(30-10)) Q 10 = (6) (0.5) Q 10 = 2.5