Living in a Carbon World
Carbon is everywhere! Carbon is the fourth most abundant element in the universe and is the building block of life on Earth. Carbon exists in pure forms such as a diamond or graphite or in the millions of different kinds of carbon compounds scientists have currently identified. We use carbon compounds such as wood to build and heat our homes. Carbon compounds are responsible for combustion in the gas tanks of our cars and in the muscles of our bodies. This small six-proton atomic element carbon is central to life, gives us fuel for energy, and is critical to regulating our climate. Carbon can exist in gases, liquids and solids. In the non-living environment, we can find carbon in CO2 and other gases, carbonate rocks, coal, oil and gasoline. In the living environment, carbon can exist in proteins, carbohydrates, fats and nucleic acids and other carbon compounds made by living organisms. Carbon can exist in very small molecules with only two atoms such as carbon monoxide up to molecules that contain thousands of atoms such as proteins and DNA.
In Part A of this lab, you will trace the pathway of carbon from the atmosphere into trees where carbon can be stored for hundreds to thousands of years.
In Part B of this lab, you will go outdoors and measure the amount of carbon in a tree in your neighborhood.
In Part C, you will learn how important biosphere processes convert carbon compounds into new and different carbon compounds as carbon moves through the carbon cycle. Using a ball-and-stick carbon molecule kit and 3-D structures of carbon compounds, you will demonstrate how carbon can bond with other atoms and create many different types of carbon compounds.
After completing this investigation, you should be able to:
- explain why carbon atoms can form the basis of millions of different types of carbon compound molecules.
- describe how the carbon atoms in CO2 absorbed via plant photosynthesis provide the carbon atoms for all of the new carbon compounds a plant produces.
- explain how carbon compounds are transformed in four processes that are critical to the carbon cycle: photosynthesis, cell respiration, biosynthesis and combustion.
- apply skills to measure the amount of carbon in a tree.
Keeping Track of What You LearnThroughout these labs, you will find three kinds of questions.
- Checking In questions are intended to keep you engaged and focused on key concepts and to allow you to periodically check if the material is making sense. These questions are often accompanied by hints or answers to let you know if you are on the right track.
- Stop and Think questions are intended to help your teacher assess your understanding of the key concepts and skills you should be learning from the lab activities and readings.
- Discuss questions are intended to get you talking with your neighbor. These questions require you to pull some concepts together or apply your knowledge in a new situation.