October 15, 2013
Cited from the lab guide cellular respiration is the process of changing the chemical energy of organic molecules into a type that can be used by organisms. The equation for this process:
C6H12O6 + 6O2 -> 6CO2 + 6H2O + energy
If enough oxygen is available, glucose may be oxidized and from looking at the equation above, if glucose is the energy source, then for every molecule of oxygen that is consumed, one molecule of carbon is produced. In simpler terms, carbon dioxide is formed as oxygen is used. The pressure, due to C02, might cancel out any change due to the consumption of oxygen. To fix this issue, the chemical potassium hydroxide will be added that will selectively take out C02. Potassium hydroxide will chemically react with carbon dioxide by the following equation:
C02 + 2 KOH -> K2CO3+ H20
A microrespirometer is the system used to measure cellular respiration. As long as the volume and temperature in the microrespirometer does not change, the pressure changes in the microrespirometer are directly relative to a change in the amount of gas in the microrespirometer. Therefore, by comparing separate microrespirometers, each with different test subjects within, we can observe the different rates at which cellular respiration occurs.
In this experiment, the rate of cellular respiration in the germinating peas will be higher than that of the glass beads; non-germinating peas; and seeds mixed with glass beads.
3 mm of germinated seeds
3 mm of non germinated seeds
3 mm of glass beads
3 mm of plants seed with glass beads
Thin-stemmed plastic dropping pipettes
40 microliter capillary tubes
Absorbent and nonabsorbent cotton
15% solution of KOH, potassium hydroxide solution
Tub of water
Begin the experiment by setting up microrespirometers. First, put a absorbent cotton at the end of the microrespirometer....