Cellular Respiration (with plot)

Summary

This laboratory setup allows students to measure the concentration of carbon dioxide inside a sealed chamber containing seeds of similar size to each other. Students can choose between different experimental conditions: seeds previously soaked in distilled water or in an acetic acid solution at room temperature (24 ± 1)°C, or unsoaked seeds (not activated).

 

Versions of this laboratory

This version of the laboratory displays a plot at the end of each experiment and allows students to download the data in a spreadsheet. This allows students to analyze the results without needing to gather and plot the data themselves.

An alternative version of the lab exists (Cellular Respiration) in which the plot and the data are not available. That way, in order to analyse the results and reach proper conclusions, students need to gather and plot the data themselves from the discrete sensor readings, similarly to how they would do so in a traditional hands-on lab.

 

Carbon dioxide release in plant respiration

Cellular respiration is one of the vital functions carried out by all cells, through which various organic compounds are broken down and the energy needed for other processes is released.

The exchange of gases at a macroscopic level is evidence of the energy transformation processes that occur in cells. In the presence of oxygen, carbon dioxide is released as a byproduct of cellular respiration. This emission of carbon dioxide is essential for understanding the metabolism of living beings and its consequences in ecosystems.

 

Seed Activation

The imbibition or absorption of water by seeds is an essential process for activating their metabolism and for breaking dormancy, thus preparing the seed for germination. This phenomenon occurs by immersing the seeds in water or aqueous solutions for a specified period, such as soaking in distilled water or acetic acid. The duration and conditions of imbibition directly influence the metabolic activation of the seed, which is reflected in the rate of carbon dioxide release during the cellular respiration process. The metabolic rate can vary depending on the species and chosen imbibition conditions.

 

Experiments & Setup

The experimental device is equipped with a gaseous carbon dioxide sensor and a hermetic chamber. Students have the option to select from the three previously detailed seed activation experimental conditions.

In all experiments, seeds of the same species with similar sizes are used, which facilitates the comparison of results.

 

Learning Objectives

• Understand the scientific endeavor through the development of a controlled experiment and the interpretation of data related to biological processes.
• Relate the release of carbon dioxide under different experimental conditions to cellular respiration, differentiating the levels of organization of matter.
• Identify cellular respiration as an essential characteristic of living beings and understand the importance of the energy transformations it entails.