Lab Primer: Cellular Respiration
Living systems require free energy and matter to maintain order, to grow, and to reproduce. Energy deficiencies are not only detrimental to individual organisms, but they cause disruptions at the population and ecosystem levels as well. Organisms employ various strategies that have been conserved through evolution to capture, use, and store free energy. Autotrophic organisms capture free energy from the environment through
photosynthesis and chemosynthesis, whereas heterotrophic organisms harvest free energy from carbon compounds produced by other organisms.
In cellular respiration, free energy becomes available to drive metabolic pathways vital to cellular processes primarily by the conversion of ADP → ATP. In eukaryotes, respiration occurs in the mitochondria within cells.
If sufficient oxygen is available, glucose may be oxidized completely in a series of enzyme-mediated steps.
In this lab, we'll observe and measure the rate of cellular respiration in peas. To do this, we'll build our own respirometers which work by trapping the the carbon dioxide produced during respiration to cause a pressure change in the reaction vessel allowing for rate to be calculated.
This video explains the concepts behind the lab, and this one shows us how to set the whole thing up.
Investigation 6 - Cellular Respiration (For Reference)