Cellular Respiration

Cellular Respiration

Variables

• The independent variables were temperature, metabolic state of the seed, and type of seed. For temperature, the conditions were 10°C and room temperature. For the metabolic state of the seed, the conditions were germinating and non-germinating. For the type of seed, the conditions were sunflower, bean, and corn.

• The dependent variable was the rate of cellular respiration. The rate of cellular respiration was measured by the change in oxygen.

Purpose

• To determine the effect of temperature on the rate of cellular respiration.

• To determine the effect of the metabolic state of the seed on the rate of cellular respiration.

• To determine the effect of the type of seed on the rate of cellular respiration.

Procedure

First set up the bath temperature to 10°C. Then place KOH pallets at the bottom of the vials. Handle the KOH with forceps. Next, place cotton on top of the KOH. Then fill the graduated cylinder to 50mL and place 25 germinated seeds in it. Determine the H2O displacement to determine the volume. Then record. Refill the graduated cylinder to 50mL and place 25 non-germinating seeds in it and determine the volume. Add beads until the volume is equal to that of the germinated seed volume. Refill the graduated cylinder to 50mL and add glass beads to obtain the same volume. Moisten the each stopper and place it into each of the vials. Lay the vials in the water for 10 minutes. After 10 minutes, collect data for 20 minutes. Once data is collected, disable the sensors, dispose of the KOH, and clean up the rest of the materials.

Conclusion

• Temperature

As temperature increases, pressure increases. The rate of cellular respiration at room temperature for a non-germinating sunflower seed is -0.0037 (kPa/min), while the rate of cellular respiration at 10°C for a non-germinating sunflower seed is 0.0078 (kPa/min). A negative rate of cellular respiration means there was an increase in pressure. Temperature and pressure are directly proportional because if you increase the temperature of a gas in a container, then the gas particles will move faster causing more collisions and an increase in pressure.

• Metabolic State of Seed

A germinating seed will have a higher rate of cellular respiration compared to a non-germinating seed. The rate of cellular respiration for a germinating sunflower seed at room temperature was 0.0125 (kPa/min), while the rate of cellular respiration for a non-germinating sunflower seed at room temperature was -0.0037 (kPa/min). The rate of cellular respiration