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 seeds in a fertilizer and non-fertilizer environment will allow students to determine the effect of nutrients (nitrogen, phosphorus, iron etc) on carbon sequestration in plants. Finally, they explore carbon molecules both by building ball-and-stick models and by interacting with Web-based molecules. Is the ability of radish plants to store carbon and grow limited by the amounts of nutrients such as nitrogen, phosphorus, and iron.
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 in chemical reactions that are critical to the carbon cycle; photosynthesis, cell respiration, combustion, decomposition and biosynthesis.
For more information about the TOPIC, read the section titled Background Information under Additional Resources below
Research by Michigan State indicates that students have a very limited understanding of how the global carbon cycle works. See What Carbon Cycle? College Students Lack Scientific Literacy, Study Finds Specifically, this research indicates that students do not understand the processes that transform carbon nor do they understand that most of a tree's growth comes from atmospheric CO2 and water. Labs 1A and 1B are designed to address these mis-conceptions and lack of understanding of basic carbon processes that underpin the carbon cycle.
In Part A: Students consider the question, "Where does a tree get its mass? They then set up an experiment, growing radish or corn 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. This site uses JAVA which could present from problems for schools. You easily see beautiful J-mol molecules on the IPAD app, "Nice Molecules." This app allows students to rotate and enlarge many different carbon compounds and access information about each molecule.
Materials: Molecular model kits can be ordered from Lab-Aids Inc 17 Colt Court , Ronkonkoma, NY 11779 (800) 381-8003.
For each lab group, you will need 12 carbon atoms, 12 hydrogen atoms and 18 oxygen atoms.
There are three ways you can order the molecules:
1. Order a "Molecules of Life" kit. https://lab-aids.com/kits-and-modules/details/molecules-of-life-modeling Item # 505 $108.95
You will need to order two kits in order to have enough oxygen atoms.
2. You can order "Molecules of Life "EXPAND -a-KIT" packages which provide enough material for one additional group of 4.
Item # = #505EL $12.25 per package You will need to order extra bags so you will have enough oxygen atoms.
3. You can order individual colors of molecules in packages of 100 @ approximately $14.95 per package (given the current price).
This is the best way to order them. It allows flexibility in ordering for the numbers and types of groupings you would like to do in your classroom and with a little bit of work, you can reconfigure them into the same color-coding system as the Jmol molecules. If you want your students to make jmol molecules that have nitrogen atoms in them (for example amino acids) you will have to order one bag of nitrogen molecules.
However, VERY IMPORTANT: Red and Blue atoms come as tetrahedral atoms so you will have to reconfigure them by cutting some prongs off. The extra prongs snip off easily with a good pair of sissors.
Because the atoms come in bags of 100, you will need to determine how many bags of each type of atom (carbon, hydrogen, oxygen, and *nitrogen(optional)) you will need to order to suit your personal needs (# of class groupings, making other optional *nitrogen-based jmol molecules like amino acids etc).
white covalent bonds - you will need 36 bonds per group to make glucose
carbon - you will need 12 carbon atoms per bag to make one molecules of glucose
oxygen - you will need 18 oxygen atoms to make one molecule of glucose
hydrogen - you will 12 hydrogen atoms to make one molecule of glucose
Click below for ordering the 100/pk of atoms
The oxygen and nitrogen atoms will have to be modified/reconfigured by snipping of prongs from the tetrahedral.
Jmol molecules: Unfortunately, the Jmol molecules use a different color-coding system than the non-Jmol "Molecules of Life" atoms.
In order to get the molecules with the same color-coding as the Jmol molecules (black = carbon, red = oxygen, blue = nitrogen, white = hydrogen), you will have to call and ask for a special order. These items are not in the catalog so you will have to speak to a customer representative. Then when you receive the materials, you will have to "reconfigure" the oxygen (#530 A-BT2) and nitrogen (#530A-RT) atoms according to the instructions in boldface type below.
# 530A-T5 Covalent bonds, 100/pk $14.65 per bag
#530A-BT Molecular Model Component, Tetrahedral Bond, Carbon Sp3 Hybrid (black), pk/100 $14.65 per bag (4 bonds)
#530A-WS Molecular Model Component, single bond, Hydrogen (white), pk/100 $14.65 per bag (1 bond)
#530 A-RT Molecular Model Component, Tetrahedral Bond, Nitrogen (red), pk/100 $14.65 per bag (for Jmol, red atoms are oxygen atoms so you will have to"reconfigure" these red atoms into oxygen atoms by cutting off two of the bond "prongs." Remember that oxygen forms two bonds.)
#530 A-BT2 Molecular Model Component, Tetrahedral Bond, Oxygen (blue), pk/100 $14.65 per bag (for Jmol, blue atoms are nitrogen so you will have to cut off two of the bond "prongs" in order to make these into oxygen atoms)(for Jmol, blue atoms are nitrogen atoms soyou will have to "reconfigure" these blue atoms into nitrogen atoms by cutting off one of the bond "prongs." Remember that nitrogen forms three bonds.
Printable MaterialsTo 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 (under revision)
- 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 (under revision)
- Stop and Think Questions Lab 1 A and B (Microsoft Word 2007 (.docx) 47kB Feb21 13) Stop and Think Questions for Lab 1A and Lab 1B
Teaching Notes and Tips;
It is important that you germinate your seeds at least 4 days before you start the module. If you would like to be able to collect and analyze data from the plant experiment at the end of Lab 1A, consider setting up this experiment 3 weeks before you begin the "Climate and the Carbon Cycle" module.
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.
- Teacher Notes: "The Effect of Fertilizer on Carbon Sequestration." (Microsoft Word 2007 (.docx) 250kB Nov4 11) Teacher's Notes on Plant Experiment. (Under revision)
In LAB 1B, 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 will build a glucose molecule from 6 carbon dioxide molecules and 6 water molecules. Students 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 throughout 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.
- You can assess student understanding of topics addressed in this investigation by grading their responses to the Stop and Think questions.
- When students have finished the plant lab, they graph and analyze the data. Teachers may choose to have students write a formal lab report based on team data and/or whole class data.
Assessment for end of Lab 1 (Microsoft Word 2007 (.docx) 126kB Feb21 13)
State and National Science Teaching Standards
TO BE PROVIDED LATER
Developer will correlate activity to standards listed at this site:National Science Education Standards (SRI)
Background InformationBacterial Nitrogen Fixation
The Nitrogen Cycle