Lab 1:Keeping Up With Carbon

The lab activity described here was created by Candace Dunlap of TERC for the EarthLabs project.

Use the button at the right to navigate to the student activity pages for this lab. To open the student pages in a new tab or window, right-click (control-click on a Mac) the "Open the Student Activity" button and choose "Open Link in New Window" or "Open Link in New Tab."

Investigation Summary and Learning Objectives

Students are briefly introduced to the essential role that carbon plays in life as we know it. Next they set up a controlled experiment that will require a couple of weeks to complete, planting some seeds in a standard atmosphere environment, some in an environment without fertilizer, and some without fertilizer but in a carbon-dioxide-enhanced environment. These three environmental conditions will allow them to compare the possible influence of CO2 and soil nutrients on plant growth and thus the ability of trees to sequester carbon. Finally, they explore carbon molecules both by building ball-and-stick models and by interacting with Web-based molecules.

After completing this investigation, students will be able to:

• explain why carbon can be transformed into so many different forms of molecules
  
• explain how carbon compounds are transformed into three chemical reactions that are critical to the carbon cycle; photosynthesis, cell respiration, and combustion.
  

For more information about the TOPIC, read the section titled Background Information under Additional Resources below

Activity Overview

In Part A: Students consider the question, "Where does a tree get its mass? They then set up an experiment, growing radish seedlings in various environments, to help them address this question.

In Part B: Students use molecular ball-and-stick models to explore carbon's potential for combining with other common elements such as hydrogen, oxygen, and nitrogen to form a variety of molecules. They "visualize" important carbon compounds such as chlorophyll and glucose by looking at their Jmol images. They can also interactively explore 3-D representations of these molecules accessing the molecules at the "World of Molecules" Web site--the Interactive Library- which allows them to

Printable Materials

To download one of the PDF or Word files below, right-click (control-click on a Mac) the link and choose "Save File As" or "Save Link As."

• Plant Data Table for Students (Microsoft Word 2007 (.docx) 84kB Mar12 12) Student Data Table: Plant Experiment
  

• Students' Lab Instructions - "The Effect of Fertilizer on Carbon Sequestration." (Microsoft Word 2007 (.docx) 240kB Nov4 11) Student's Lab Instructions: The Effect of Fertilizer on Carbon Sequestration in Plants

• Stop and Think Questions Lab 1 A and B (Microsoft Word 2007 (.docx) 47kB Feb21 13) Stop and Think Questions
  

Teaching Notes and Tips

In LAB 1 -A, students begin the module with by examining the capacity of trees and forests to remove CO₂ from the atmosphere and sequester it in their tissues and structures. Trees are composed largely of water and a carbon compound called cellulose. Cellulose is the fibrous material that makes up the woody tissue of trees. The water content of trees varies from less than 10% of the tree's weight to more than 50%, depending on the species; the average is closer to 25%. The biomass (dry weight) of a tree comes essentially from cellulose - a complex carbon compound made of carbon, hydrogen, and oxygen atoms. More than 50% of that biomass comes from carbon. All of this carbon comes from atmospheric carbon dioxide. In the process of photosynthesis, carbon dioxide is combined with water to produce oxygen and the sugar that provides energy and building materials of carbon, oxygen and hydrogen atoms.

The plant experiment they set up in this lab will give them solid data on the ability of plants to take in and sequester CO₂ and understand how soil nutrients, such as nitrogen, limit CO₂ sequestration. Comprehensive notes on the plant experiment are in the link below.

Radish Powerpoint

• Teacher Notes: "The Effect of Fertilizer on Carbon Sequestration." (Microsoft Word 2007 (.docx) 250kB Nov4 11) Teacher's Notes on Plant Experiment

• Plant Data Table for teachers (Microsoft Word 2007 (.docx) 145kB Mar12 12) Plant Data Table with sample data (for teachers only)

In LAB 1-B, students build a myriad of carbon compounds from six carbon dioxide molecules and six water molecules - the same building materials that trees use to build their structures. Students should not be concerned about using the molecules to build a particular carbon compound such as a glucose sugar or an amino acid). Instead, they need to construct an understanding of the many different forms and structures carbon compounds can take because of the bonding nature of carbon. The term "carbon compound" should be used through all of the investigations in this module, where appropriate. For classroom management, have students take apart the molecules they built before the end of class in order to prep for the next class coming in.

Also - See the following tables of information for Labs 1-7

• Activities and Materials: Table Labs 1-7 (Microsoft Word 2007 (.docx) 125kB Mar12 12) TABLE FOR TEACHERS; Activities and Necessary Materials for Labs 1-7. This table will give you a list of all the hands/on and minds-on activities for the entire module that require special materials.
  

• Videos and Interactives: Table Labs 1-7 (Microsoft Word 2007 (.docx) 153kB Mar12 12)TABLE FOR TEACHERS: Videos and Interactive for Labs 1-7 A list of videos and interactives with links. Some videos are available from more than one source e.g. YOUTube, Vimeo etc.

Assessment

State and National Science Teaching Standards

Additional Resources

Background Information

Carbon Sequestration:
Carbon Sequestration in Agriculture and Forestry

Environmental Scientists Find Tree Combo for Carbon Sequestration

Carbon Sequestration in Forests

Content Extension