Cellular Respiration of Pea Plants
Colleen Hamilton
AP Lab 4: Determining the Rate of Cellular Respiration of Peas at Varying Temperatures and Stages of Germination
I. Purpose and Intro
The purpose of this lab is to determine the rate at which germinating peas respirate at varying temperatures and stages of germination.
Cellular respiration is the set of metabolic reactions and processes that takes place in an organism’s cells in order to create ATP from sugar. It occurs in the mitochondria and comprises three stages: glycolysis, the citric acid cycle, and oxidative phosphorylation. The process is as follows:
C6H12O6 + 6O2 6CO2 + 6 H2O + 36 or 38 ATP Through determining the rate of oxygen consumption, the rate of respiration can be determined. In this experiment, all carbon dioxide produced through respiration combines with KOH in the following reaction:
CO2 + 2KOH K2CO3 + H2O Carbon dioxide is removed when it combines with potassium hydroxide. This creates a change in volume of the gas in the respirometer. Because the amount of oxygen consumed and carbon dioxide produced have the same molar ratio (6:6), the rate of change in volume of gas is directly related to oxygen consumption, and the rate of cellular respiration. The change in the volume of the gas that takes place is analyzed through the use of submerged respirometer and the use of the universal gas law. Through the equation PV=nRT, we know that if temperature and volume remain constant, gases will flow from regions of higher to lower pressure. The consumption of oxygen and carbon dioxide’s reaction with potassium hydroxide cause a change in the gas’ volume, and the pressure inside the respirometer decreases. This causes water to move along the pipette tip as gas flows into the respirometer. A change in volume of gas can thus be recorded, and this relates to oxygen consumption and the rate of cellular respiration taking place within the peas. The germinating peas in this experiment undergo cellular respiration.
AP Lab 4: Determining the Rate of Cellular Respiration of Peas at Varying Temperatures and Stages of Germination
I. Purpose and Intro
The purpose of this lab is to determine the rate at which germinating peas respirate at varying temperatures and stages of germination.
Cellular respiration is the set of metabolic reactions and processes that takes place in an organism’s cells in order to create ATP from sugar. It occurs in the mitochondria and comprises three stages: glycolysis, the citric acid cycle, and oxidative phosphorylation. The process is as follows:
C6H12O6 + 6O2 6CO2 + 6 H2O + 36 or 38 ATP Through determining the rate of oxygen consumption, the rate of respiration can be determined. In this experiment, all carbon dioxide produced through respiration combines with KOH in the following reaction:
CO2 + 2KOH K2CO3 + H2O Carbon dioxide is removed when it combines with potassium hydroxide. This creates a change in volume of the gas in the respirometer. Because the amount of oxygen consumed and carbon dioxide produced have the same molar ratio (6:6), the rate of change in volume of gas is directly related to oxygen consumption, and the rate of cellular respiration. The change in the volume of the gas that takes place is analyzed through the use of submerged respirometer and the use of the universal gas law. Through the equation PV=nRT, we know that if temperature and volume remain constant, gases will flow from regions of higher to lower pressure. The consumption of oxygen and carbon dioxide’s reaction with potassium hydroxide cause a change in the gas’ volume, and the pressure inside the respirometer decreases. This causes water to move along the pipette tip as gas flows into the respirometer. A change in volume of gas can thus be recorded, and this relates to oxygen consumption and the rate of cellular respiration taking place within the peas. The germinating peas in this experiment undergo cellular respiration.