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Cellular and Whole-Animal Respiration. GK-12 Workshop II Ashley Vorhees and Sarah Park Cesar E. Chavez High School. Cricket Respiration Lab. Students will measure oxygen consumption in crickets at different temperatures using simple respirometers . Water level. Pipette. Why teach this?.
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Cellular and Whole-Animal Respiration GK-12 Workshop II Ashley Vorhees and Sarah Park Cesar E. Chavez High School
Cricket Respiration Lab Students will measure oxygen consumption in crickets at different temperatures using simple respirometers. Water level Pipette
Why teach this? • Integrates into cell bio curriculum
Why teach this? • Integrates into cell bio curriculum • Cell curriculum can be abstract and difficult to relate to
Why teach this? • Integrates into cell bio curriculum • Cell curriculum can be abstract and difficult to relate to • Students learn about cell functions in the context of whole-animal function
Overview of Module • Pre-Lab Lecture Notes • Cellular respiration • Pre-Lab Worksheet • Effects of temperature on metabolism • Lab Experiment • Measuring oxygen consumption in crickets • Follow-up Questions • Reinforce understanding of lab • Extension Activity • Extrapolating human MR from cricket MR
III. Cricket Respiration Lab As cricket consumes O2, pressure inside chamber decreases O2 O2 Water level O2 KOH O2 O2 Pipette
III. Cricket Respiration Lab As cricket consumes O2, pressure inside chamber decreases O2 O2 Water level O2 KOH O2 Pipette CO2
III. Cricket Respiration Lab As cricket consumes O2, pressure inside chamber decreases O2 O2 Water level O2 KOH CO2 Pipette CO2
III. Cricket Respiration Lab As cricket consumes O2, pressure inside chamber decreases O2 O2 Water level CO2 KOH CO2 Pipette CO2
III. Cricket Respiration Lab As cricket consumes O2, pressure inside chamber decreases O2 Water level CO2 CO2 KOH CO2 Pipette CO2
III. Cricket Respiration Lab Amount of water that enters pipette is directly proportional to amount of O2 consumed by the cricket Measure volume difference and divide by minutes MR = mL O2 per minute O2 Water level CO2 CO2 KOH CO2 Pipette CO2
IV. Data Collection • Graph the results • Should show linear increase in metabolic rate with temperature
Materials Timeline • Live crickets (large) • Small vials • Rubber stoppers • Graduated pipettes (≤2mL) • Cotton balls • 15% KOH solution • Water baths • Thermometers • Ice *Needs to be completed in 1 day
Assessment • Fill-in Notes • Pre-Lab Worksheet • Data Table • Comprehension Questions • Extension Activity
Today… • Work in your RS/CT pairs • 11:00-11:45 Set up and perform the cricket respiration experiment (Stations 1-4) • 11:45-12:00 Walk-through of Extension Activity
Extension Activity • Purpose • Help students see connection between module content and their own physiology • How • Estimate human metabolic rate based on cricket metabolic rate • Reinforces concepts: • Your cells use same cellular processes to make ATP as a cricket • Body size (# of cells) determines how quickly you use energy
What factors determine metabolic rate? • Temperature • Phylogeny • Body Mass Metabolic rate scales with body mass according to: MR = aM0.75 MR – metabolic rate M – body mass a – constant that depends on the animal in question
Scaling of metabolic rate Mass = 10 g Mass = 20 g MR = 10 mL O2/min MR = 16.8 L O2/min MR = aM0.75
How can we use this equation? • Two equations with and unknown. • Instead of having students solve both, we combine into one that uses a relative mass:
200,000 0.02 200,000 9457 189 0.02 0.4 0.0004 Body Mass Temperature