Materials Included In Kit

Additional Materials Required

Prelab Preparation

1. Cut out one die template on the solid lines.
2. Fold the die sections and tabs inward on the dashed lines.
3. Use tape or glue on the tabs to make the die template into a cube. Note: The final fold may need to be taped to hold the die together well.
4. Repeat for the other die templates.
5. Cut apart each station sign on the solid lines.
6. Make a tent-fold with each sign on the dotted lines.
7. Place one sign and its respective die at each station around the classroom. Note: An extra die is provided for the atmosphere and ocean stations to avoid long wait times.

Safety Precautions

The materials in this activity are considered nonhazardous.

Lab Hints

• Enough materials are provided in this kit for 30 students working individually. This activity can reasonably be completed in one 50-minute class period. The Prelab Questions may be completed before coming to class, and the Post-Lab Questions may be completed the day after the activity.
• The dice templates and station signs are printed on card stock for durability with repeated use. Laminate the dice templates and station placards for even greater durability.
• Assign students to different stations before the activity begins. Three students per die at each station to begin with is a reasonable number to avoid long waiting periods for the dice.
• If desired, photocopy the dice templates on colored card stock before cutting out and make two or three dice for each station.
• Be sure the correct die is placed at each station. The name of each station is printed in italics on the lower right corner of each die face.

Teacher Tips

• This is a great interactive exercise to help students understand the nature of the carbon cycle.
• Place photos depicting each of the reservoirs represented by the particular stations.
• If time allows, instruct students to complete the activity a second time, starting at a different station, and then compare their two “adventures” through the carbon cycle.
• The carbon cycle contains many intricate biochemical processes. As an extension, group students into the different stations and ask them to research specific processes in which carbon moves to and from their respective reservoir.
• As a follow-up activity, use Understanding Your Carbon Footprint—Student Activity Kit, available from Flinn Scientific (Catalog No. AP7322).

Answers to Prelab Questions

1. Explain the role of each of the following in the carbon cycle and give an example for each.
   1. Autotrophs

      Autotrophs have the ability to make their own food source. Through photosynthesis, autotrophs use CO₂ in conjunction with water and energy in the form of light to yield glucose and O₂. Autotrophs are crucial to the removal of CO₂ from the atmosphere. Autotrophs include plants, phytoplankton and algae.

   2. Heterotrophs

      Heterotrophs are a source of CO₂ in that they produce CO₂ via cellular respiration. Cellular respiration breaks down glucose and oxygen into CO₂, water and energy in the form of ATP. The CO₂ is then exhaled into the atmosphere. Heterotrophs include animals, fungi, bacteria and protists.

   3. Decomposers

      Decomposers are a subgroup of heterotrophs that are able to break down organisms or the waste products of organisms. Decomposers include fungi, worms and bacteria.

2. Explain how deforestation leads to increasing CO₂ concentration in the atmosphere.

   Many trees and other plants are lost during deforestation events, resulting in the loss of a large number of photosynthetic organisms. This results in far less CO₂ absorption from the atmosphere.

3. Using Figure 1 as a reference, name all the sources from which carbon is released into the atmosphere.

   According to Figure 1, the following are sources from which carbon is released into the atmosphere: plants, animals, decomposers, oceans, rocks and industry (burning of fossil fuels).

Sample Data

Answers to Questions

1. Consider your journey through the carbon cycle.
   1. Were you able to make it through the entire carbon cycle?

      No—nine of the ten stations were visited in the journey.

   1. If not, which reservoirs were not reached?

      The animal station was not visited in the journey.

2. Compare your carbon cycle adventure with a classmate’s.
   1. Describe several ways in which the two adventures are different.

      The path travelled was in a different order; only four stations were visited in one and nine in the other; more time was spent in certain reservoirs for one journey and in different reservoirs for the other, etc.

   2. How are they alike?

      Both journeys involved photosynthesis, diffusion and sedimentation, etc.

3. Why is the decomposition of waste and dead organisms important in this cycle? What would happen if this process did not occur?

   Decomposition allows for the recycling of carbon from waste and dead organisms. If decomposition did not occur, carbon would not be released back into the flowing cycle; it would instead be stuck within the dead matter. Decomposition is an important source of carbon in the carbon cycle.

4. Explain the effect carbon has on climate.

   Carbon is a greenhouse gas, meaning it traps heat energy from the sun. Carbon in the atmosphere allows for the Earth to stay warm enough for life to thrive. The cycling of carbon into and out of the atmosphere helps to maintain temperatures over time.

5. What are some ways in which humans have impacted this cycle?

   Humans mine fossil fuels from the Earth to burn for energy. Upon combustion of fossil fuels, the carbon is released into the atmosphere in the form of inorganic carbon dioxide. Deforestation is another human-driven action that impacts the carbon cycle. The decrease in photosynthesizing plant-life results in a decrease of CO₂ absorption from the atmosphere. Both the burning of fossil fuels and deforestation by humans over time has led to an increase in the CO₂ concentration of the atmosphere.

References

Diugokencky, Ed and Pieter Tans, NOAA/ESRL www.esrl.noaa.gov (accessed April 2016).

Riebeek, Holly. (2011) The Carbon Cycle. NASA Earth Observatory. www.earthobservatory.nasa.gov/Features/CarbonCycle (accessed April 2016).

Introduction

Carbon is the key to life on Earth—all living organisms are composed of carbon, rely on carbon for energy and contribute to its cycling among systems. The carbon cycle is the continuous movement and storage of carbon among these systems.

Concepts

• Carbon cycle
• Greenhouse gases
• Heterotrophs vs. autotrophs
• Greenhouse effect

Background

Carbon is essential to all living organisms and a fundamental component of many chemical processes. The carbon cycle, shown in Figure 1, depicts the movement of carbon among Earth’s oceans, atmosphere, biosphere and geosphere. The carbon cycle is vastly important for life on Earth.

A consumer, or heterotroph, is an organism that receives energy by consuming other organisms. Heterotrophs, including animals, fungi and some bacteria use cellular respiration to metabolize the consumed organism (see Equation 1). During this process, the inorganic byproduct CO₂ is produced and released into the atmosphere. Decomposers are heterotrophs that feed upon dead organisms and waste products of other organisms, helping cycle nutrients back into the ecosystem. Producers, or autotrophs, have the ability to produce their own food source by means of photosynthesis or chemosynthesis. Photosynthetic organisms, such as plants and phytoplankton, acquire inorganic CO₂ from the atmosphere. During photosynthesis, the carbon is converted into organic forms that can be used by consumers. At the same time, plants are also executing cellular respiration, releasing CO₂ back into to atmosphere (see Equation 2). Most of Earth’s carbon is stored in rocks, remaining there for very long periods of time. Volcanic eruptions and chemical weathering release stored carbon to the atmosphere. Carbon layers in the soil are created by the delayed or partial decomposition of dead organisms. Over time this sediment of mud and carbon is compressed by heat and pressure into true rock, limestone. As carbon layers deep underground are heated and subjected to intense pressure, coal and other fossil fuels are produced over millions of years.

The second most abundant carbon reservoir is the ocean. Carbon dioxide gas diffuses back and forth between the atmosphere and surface ocean. As carbon sinks into depths of the ocean, the diffusion exchange slows and carbon remains stored for long periods of time. Carbon is also being stored and released by photosynthesis and respiration of various organisms living in the ocean. As these organisms die and decompose on the ocean floor, the slow formation of rock or fossil fuel may begin.

Greenhouse gases, such as carbon dioxide, increase the overall temperature of the atmosphere by trapping and holding heat energy before releasing it into space. This is known as the greenhouse effect. Without it, the daily temperature would be much lower and nights would be unbearably cold. Carbon dioxide and other greenhouse gases are vastly important as they allow for the ability to inhabit the Earth. However, the widespread burning of fossil fuels and deforestation have led to a trend of increasing CO₂ concentration in the atmosphere and oceans. Higher concentration of greenhouse gases in the atmosphere means more heat energy can be trapped. As of 2015, the average atmospheric concentration of CO₂ has increased 30% from 100 years ago and more than 40% from the average before widespread use of fossil fuels.

Experiment Overview

The purpose of this experiment is to track a carbon atom through the stages of the carbon cycle by moving from one station to another based on the roll of Carbon Cycle Dice at each station. The various stages experienced and the amount of time spent at each will be recorded.

Materials

Prelab Questions

1. Explain the role of each of the following in the carbon cycle and give an example for each.
   1. Autotrophs
   2. Heterotrophs
   3. Decomposers
2. Explain how deforestation leads to increasing CO₂ concentration in the atmosphere.
3. Using Figure 1 from the Background section as a reference, name all the sources from which carbon is released into the atmosphere.

Safety Precautions

Please follow all classroom safety guidelines.

Procedure

1. Begin at one of the eight stations assigned by the instructor. Note: Each station represents one of the storage areas in the carbon cycle: atmosphere, plant, animal, decomposer, rock, fossil fuel, industry and ocean.
2. Record the starting station in the Data Table on the Carbon Cycle Adventure Worksheet.
3. Roll the Carbon Cycle Die found at this station. Note: If other students are at the same station, take turns rolling the die. Follow the directions for your roll only.
4. Note the directions on the side of the die facing up. Record the event designated on the die under Event.
5. Record the station designated as “Go to” on the die for Roll 1 in the data table. If directed to stay, rewrite the name of the current station.
6. Move to the station indicated by the roll of the die (or stay at the same station if directed).
7. Repeat steps 3–6, recording the event, process, and the next station for each roll of the die until 20 rolls have been completed or the time allotted by the instructor is up.
8. Complete the Carbon Cycle Adventure Worksheet.

Student Worksheet PDF

11353_Student1.pdf