Heterotrophs
Animals need constant energy to organize cells, tissues, organs.
- Heterotrophic All Animals
- Require organic molecules.
- Harvest energy by breaking bonds in food.
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- Lipids are for long-term energy storage.
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- Carbs are for short-term energy release.
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- Proteins are necessary for the building blocks.
Three Types of Heterotrophic Feeding
- Predation
- Suspension feeding
- Symbiosis
Energy
- Essential
- Can't make your own
- Required to obtain via your diet
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Amino Acids (8 of 20 are essential)
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Organic Atoms
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Fatty Acids
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Nutrients
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Elements
Food energy values measured by amount of heat food produces when burned in the presence of O2.
Animals burn food and give off CO₂ and H₂O.
- Calorie
- Heat to raise 1 gram of water by 1C.
- 1 kilocalorie = 1000 Calories
- Basil Metabolic Rate BMR
- The amount of O₂ consumed per gram of body mass per hour.
Thermoregulation
- Endotherms Homeotherms
- Warm-blooded
- Regulates body temp.
- Body temp stays the same.
- Costs energy to maintain.
- Ectotherms Poikilotherms
- Cold-blooded
- Can tolerate extreme temperatures.
- Body temp 'conforms'.
- Body temp matches external environment.
- Behavior can still regulate body temp.
Endotherm basil metabolic rate is affected by external temperature.
- BMR is lowest at ideal environment temperatures.
- Thermal-Neutral Zone
- Low metabolic rate at ideal temperatures.
- Warm-blooded animals hibernate into cold-blooded animals - slows metabolism.
Mechanisms for Thermoregulation
- Shivering Shivering Thermogenesis
- Muscles contract and convert ATP to heat.
- Non-Shivering Thermogenesis Brown Adipose Fat Tissue
- Performs oxidative phosphorylation in the mitochondria that converts glucose into heat instead of ATP.
- Regulation of blood glucose levels contribute to thermoregulation.
- Countercurrent Heat Exchange
- Blood to and from appendages lie next to each other so heat going to the appendages can bleed into heat going into the body core so its not lost to the environment.