Saved science fair projects:

This is a saved copy of the relevant third party website. We save only the first page of every project because we've found that the third party sites are often temporarily down. We do not save all pages of the project because copyright belongs to the third party author.

 

The Effect of Anhydrous Ammonia on the Dehydration Rate of Plant vs. Animals Cell

Student Experimenter

Researched by Brooke S.
2004-05



 

PURPOSE


The purpose of this experiment was to compare the dehydration rate of plant and animal cells exposed to anhydrous ammonia.

I became interested in this idea when a Yakima County Sheriff’s Department drug detective showed me money that had been dehydrated by anhydrous ammonia.

The information gained from this experiment could help people preserve food. Also it will help with food transportation because dehydration cuts down the weight by taking away the moisture.  This could also help space travel.


 

HYPOTHESIS


My hypothesis was that the animal cells would dehydrate more completely and faster than the plant cells.

I based my hypothesis on an Internet site of Florida State University that said, “plant cells have a rigid wall surrounding the plasma membrane” it also said that “animal cells don’t have a cell wall.” This means that the plant cell has a harder outside with the rigid cell wall and the animal cell doesn’t, so it should be easier to take all the moisture out.


 

 EXPERIMENT DESIGN


The constants in this study were:

  • Anhydrous ammonia
  • Temperature
  • Size
  • Time
  • Brand of plastic sandwich bag


The manipulated variable was the different types of food being dehydrated.

The responding variable was the weight of the cells after being dehydrated.

To measure the responding variable I used a digital scale calibrated in grams.


 

MATERIALS

 

QUANTITY ITEM DESCRIPTION
2 Steaks
2 Pork chops
2 Chickens
2 Apples
2 Oranges
2 Celery
2 Broccoli
1 Triple Beam Balance
1 Ruler
1 Knife
3 Pints Anhydrous Ammonia
1 Box Plastic Sandwich Bags
1 Sink
1 Wooden Spoon
1 Pot
1 Strainer
1 Tongs

 


 PROCEDURES


1. Prepare foods for drying

a) Clean and dry
b) Slice food into 2 by 2 by 8 cm strips
c) Store in a sandwich bag and record weight
d) Repeat until all food has been weighed
e) For the orange take off peel

2. Find a well ventilated area
3. Put 250ml of anhydrous ammonia into the metal pot
4. Put the three pieces of beef into the same pot
5. Stir and mix the food and ammonia around with the wooden spoon
6. Take out using the tongs and/or wooden spoon
7. Put the dehydrated food back in plastic bag
8. Get new anhydrous ammonia (250ml)
9. Repeat steps 4-8 using the other foods
10. Continue until all food has been dehydrated
11. Dispose all anhydrous ammonia in a well ventilated area
12. Record new weights


 

  RESULTS


The original purpose of this experiment was to compare the dehydration rate of plant and animal cells exposed to anhydrous ammonia.

The results of the experiment were that the anhydrous ammonia dehydrated the animal cells the most with a total of 13.75 and the plant cells the least with a total of 12.25.

See my table and graph
.


 

 CONCLUSION


My hypothesis was that the animal cells would dehydrate more completely and faster than the plant cells.

The results indicate that this hypothesis should be accepted.

Because of the results of this experiment, I wonder if different types of plant and animal products would dehydrate in a similar manner.

If I were to conduct this project again I would have conducted more trials and would have used more types of food. 

 



RESEARCH REPORT

 

Introduction

Anhydrous ammonia is used for a lot of different purposes, including dehydrating items like food.  Dehydration keeps items fresh, save space, and doesn’t require refrigeration to preserve food.  Plant and animal cells are similar in some ways but different in their cell wall structure.  This could affect how easily the cells can be dehydrated.

Ammonia

The formula for ammonia is NH3.  Ammonia is a compound of nitrogen and hydrogen. Ammonia is a non-toxic, colorless gas. It is known for its irritating odor. It is extremely soluble in water. If one is going to breathe in ammonia make sure it is heavily diluted. If mixed with metal it makes a compound called ammines. During evaporation 1 gram of anhydrous ammonia requires 327 calories of heat. Ammonia is used in a lot of things.

Uses

Ammonia with more nitrogen is used for crop production. Ammonia also makes alkaline. Ammonium hydroxide is used in house cleaners and artificial fertilizers. It is used in dynamite, TNT, and other explosives. It is used to dye and scour wool, to make nylon, cotton; it is also in some vitamins, plastics, drugs, and chemicals. Anhydrous ammonia is also used for a lot of useful things.

Anhydrous Ammonia

Anhydrous means without water so when it touches something with water in it; it takes out all the moisture. Anhydrous ammonia is 82% nitrogen. It has to be handled by workers who have been educated on how to correctly use this dangerous chemical. The liquid state of the anhydrous ammonia has to be stored in tanks. The tanks have to be able to stand pressures of at least 250 PSI (pounds per square inch). If a valve is opened for the liquid to get out it turns it into the gas and can get into your body. Anhydrous ammonia is used for quite a few things.

Uses

Anhydrous ammonia is used in a lot of fertilizers and ice packs. If there is a mold growth in grain with high moisture, then some people put anhydrous ammonia on it. All the moisture will be removed and the mold will go away without the moisture. It is also used to keep crops cold while they are in storage getting ready to ship to stores. One reason anhydrous ammonia is used is for dehydration, which is a way of preserving food.

Preservation

Today someone can go to the store and pick up almost any kind of food that is preserved in some kind of package or container. Before preserving food was an option the food someone could get from the store had to either be fresh or there was probably something wrong with it because bacteria had most likely attacked it. The three main ways of preserving are freezing, canning, and dehydrating or drying.

Dehydration and Drying

Drying has been used for a very long time. Some of the reasons we have dehydrating and drying is to keep food items fresh, to save space, and dried food doesn’t have to be refrigerated.

Cells

Most cells are so small you can only see them under a microscope. All cells have a specific job to do.  Cells are like people with some things, like they need oxygen to live and need to get rid of the carbon dioxide that comes in with the air. All cells will eventually die too. There is a membrane outside every cell. The nucleus is the thing that controls genetic program.  Outside the nucleus is the cytoplasm. DNA stands for Deoxyribonucleic Acid. All plants, animals, and humans have lots and lots of cells.

Plant Cells

Plant cells are unique among eukaryotes. Chlorophyll gives plants their green color. It also makes it so the plants use sunlight to turn water and carbon dioxide into sugar and carbohydrates, which they use for fuel. Plant cells have a protective cell wall like prokaryotic ancestors. Plant cells don’t have centrioles, lysosmes, cilia or flagella unlike animal cells. They do have chloroplast, central vacuole, plasmodesmata, and a rigid cell wall.  There are about 250,000 species of plants. A small percent of plants are used for human needs, such as food, shelter, medicine, and fiber. Plants are the basis for the food web and ecosystem. Without plants no animals or human would have evolved. Animals also have a lot of cells.

Animal Cells

Animal cells do not have a cell wall. An animal cell’s nucleus and organelles have a membrane surrounding them. Animals have a greater variety of different cell types, organs, and tissues. All organisms in animals are incredibly different. Three quarters of the earth species are animals. Plants can make their own food but animals are unable to produce their own food so they rely on plants for a lot of things.

Summary

Dehydration has been used for centuries to preserve items, especially food, and to save space.  Plant and animal cells are similar but different in their cell wall structure, which probably affects how easily the cells can be dehydrated. Anhydrous ammonia is used for several industrial purposes, often to remove water from items.  With care it could be used for dehydrating food.

BIBLIOGRAPHY
  • Armbruster, David C.  “Ammonia.” World Book Encyclopedia. 1995.
  • Beck, Laurence H. “Dehydration.” World Book Encyclopedia. 1998.
  • Davidson, Michael W. “Animal Cell Structure.”
          http://micro.magnet.fsu.edu/cells/animalcell.html.
  • Davidson, Michael W. “Plant Cell Structure.”
          http://micro.magnet.fsu.edu/cells/plantcell.html.
  • “Dehydration.” http://quickcare.org/gast/dehydrate.html.
  • Johnson, Taylor J.  “Anhydrous Ammonia,” World Book Encyclopedia. 1999.
  • Knepp, Brian.  "Nitrogen and Phosphorus." Grolier Education, 1996.
  • Shutske, John M. “Using Anhydrous Ammonia Safely on the Farm.”      
         http://www.extension.umn.edu/distribution/cropsystems/DC2326.
ACKNOWLEDGEMENTS


I would like to thank the following people for helping make my project possible:

  • My parents for buying the materials needed for my experiment
  • Mr. Newkirk for helping me through my project
  • Mrs. Helms for answering my questions
  • My friend Baylee for encouraging me to keep persevering when I thought my project got too hard

Back to the Selah Homepage

Top of page

Menu of 2004-2005 Science Projects

 




Search for more science fair projects
Search science fair projects Browse science fair projects
or Ask the Mad Scientist for help with your Science Project

All Science Fair Projects