A peanut is not a nut, but actually a seed. In addition to containing protein, a peanut is rich in fats and carbohydrates. Fats and carbohydrates are the major sources of energy for plants and animals.

The energy contained in the peanut actually came from the sun. Green plants absorb solar energy and use it in photosynthesis. During photosynthesis, carbon dioxide and water are combined to make glucose. Glucose is a simple sugar that is a type of carbohydrate. Oxygen gas is also made during photosynthesis.

The glucose made during photosynthesis is used by plants to make other important chemical substances needed for living and growing. Some of the chemical substances made from glucose include fats, carbohydrates (such as various sugars, starch, and cellulose), and proteins.

Photosynthesis is the way in which green plants make their food, and ultimately, all the food available on earth. All animals and nongreen plants (such as fungi and bacteria) depend on the stored energy of green plants to live. Photosynthesis is the most important way animals obtain energy from the sun.

Oil squeezed from nuts and seeds is a potential source of fuel. In some parts of the world, oil squeezed from seeds-particularly sunflower seeds-is burned as a motor fuel in some farm equipment. In the United States, some people have modified diesel cars and trucks to run on vegetable oils.

Fuels from vegetable oils are particularly attractive because, unlike fossil fuels, these fuels are renewable. They come from plants that can be grown in a reasonable amount of time.
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Materials

• Shelled peanut
• Small pair of pliers
• Match or lighter
• Sink

Download Student Worksheet & Exercises

Procedure

ASK AN ADULT TO HELP YOU WITH THIS EXPERIMENT. DO NOT DO THIS EXPERIMENT BY YOURSELF. The fuel from the peanut can flare up and burn for a longer time than expected.

Close the drain in the kitchen sink. Fill the sink with water until the bottom of the sink is just covered.

Using a small pair of pliers, hold the peanut over the sink containing water. Ask an adult to hold the flame of a lit match or lighter directly under the peanut. When the peanut starts to burn, the lit match or lighter can be removed.

Allow the peanut to burn for one minute. MAKE SURE AN ADULT REMAINS PRESENT AND MAKE SURE TO HOLD THE PEANUT OVER THE SINK. To extinguish the burning peanut, drop it into the water. After you have extinguished the peanut, allow it to cool and then examine it carefully.

Observations

How long does it take for the peanut to start to burn? Does the peanut burn with a clean flame or a sooty flame? What color is the flame? What color does the peanut turn when it burns? Did the size of the peanut change after it has burned for several minutes?

Discussion

You should find that the peanut ignites and burns after a lit match or lighter is held under it for a few seconds. Although you only let the peanut burn for one minute as a safety measure, the peanut would burn for many minutes.

In this experiment, when the peanut burns, the stored energy in the fats and carbohydrates of the peanut is released as heat and light. When you eat peanuts, the stored energy in the fats and carbohydrates of the peanut is used to fuel your body.

Other Things to Try

Hold one end of a piece of uncooked spaghetti in a pair of pliers. Ask an adult to hold the flame of a lit match or lighter under the other end of the spaghetti. When the spaghetti starts to burn, place it in an aluminum pie pan that is in the sink. Make sure to extinguish the burning spaghetti with water when you are finished with the experiment. How does the burning of the spaghetti compare with the burning of the peanut?

Exercises 

1. What is the process called where plants get food from the sun?
   1. Osteoporosis
   2. Photosynthesis
   3. Chlorophyll
   4. Metamorphosis
2. Where does all life on the planet get its food?
3. List two ways that we could use the energy in a peanut:

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