Lab 5: Cell Respiration Respiration equation C6H12O6 + O2 CO2 + H20 + energy We will measure O2 consumed. How can we measure O2 (gas) used when CO2 (gas) is produced? - KOH – removes CO2 by forming a precipitate

After placing respirometer under water, the crickets continue to breathe. As crickets breath & use up the air in the respirometer, water moves down pipet. We can measure this as O2 used for respiration.

Respirometer set up We will use: Mealworms Only 2 respirometers

Set-up: stop after step 7 do NOT get water Data collection: - get water - begin step 8..

Ideal gas law PV = nRT - P = pressure of the gas V = volume of the gas n = number of molecules of gas R = gas constant T = temperature of gas (°K) By keeping T & P constant, V is directly proportional to n PV = nRT How will we correct for T & P and keep them constant? vial with glass beads glass beads are not alive (SHOCKER!)`, changes here reflect table bumps, etc Changes in atmospheric Temp & Pressure We must subtract out these changes Difference = initial reading – reading at time x t0 – tx Corrected difference = Worm difference – glass bead difference

Lab Notebook Format 1) Title/Date 2) Pre-Lab (Parts A, B, C as usual) 3) Purposes (2-3) 4) Personal Account Hypothesis, Procedure (all steps), Data Table, Graph, Reaction Rate Calculations 5) Discussion Questions (#1-8) Exclude #3 6) Conclusion