Cellular Respiration

Cellular Respiration Lab

1.Why is it necessary to correct the readings of the respirometers containing seeds with the readings taken from respirometers containing only glass beads? Your answer should refer to the concepts derived from the general gas law?

* PV = nRT is the formula for the inert gas law, where P is the pressure of the gas, V is the volume of the gas, n is the number of molecules of gas, R is the gas constant, and T is the temperature of the gas in degrees K. This law implies several important things about gases.

2. What happens to the volume of the gas being measured (O2 consumption or CO2 production) when the temperature or pressure changes during the experiment? If pressure and temperature remain constant, will the volume of gas in the respirometers increase or decrease?

* If the temperature and volume remain constant, then the pressure of the gas changes in direct proportion to the number of molecules of gas. Therefore the volume will increase.

3. Imagine that you are given 25 germinating pea seeds that have been placed in boiling water for five minutes. You place these seeds in a respirometer and collect data. Predict the rate of oxygen consumption (i.e., cellular respiration) for these seeds and explain your reasons.

* The rate of oxygen consumption would be increased in comparison with the rate of resperation of these seeds at room temperature.

4. Imagine that you are asked to repeat the reptile/mammal comparison of oxygen consumption, but at a temperature of 22C. Predict how these results would differ from the measurements made at 10C. Predict how the results would compare, and justify you your prediction.

* These results would show that the oxygen consumption at the temperature of 10 degrees C would be decreased in comparison with the same measurements at 22 degrees C because at the lower temperature, cellular respiration decreases

5. Imagine that you are asked to repeat the reptile/mammal comparison of oxygen...