This is a very simple demonstration that makes an impact. It illustrates energy release that occurs quickly. In the demonstration, Mr. Carter (the other science teacher at my school) visually reinforces the necessity of cellular metabolism’s small-step oxidation of glucose instead of releasing it all at once.
The materials you will need for this demonstration are as follows:
- Approximately 1 tablespoon of Potassium Chlorate
- Large test tube
- Gummy bear (or any other gummy animal)
- Fume hood (or any system to allow for the fumes to escape without engulfing the room)
- Eye protection (Lab Goggles, etc)
The solid should be heated until it melts, and then the gummy bear can be dropped in. The reaction will proceed without further effort.
The products of the reaction should be potassium chloride (white deposit near the mouth of the test tube) as well as varying amounts of soot or charred gummy bear if not all of it is used up in the reaction.
This kind of “all at once” release of energy would be catastrophic in a living organism. Fortunately, there are enzymes in place that allows it to happen in a stepwise manner.
Also, the flame color of the potassium is quite pretty 🙂
I’m not a combustion expert, so why exactly is the potassium chlorate needed? Could I just burn the gummy bear with a flame? It would burn for a few seconds, just like it does in your test tube, albiet with not pretty pink color.
That’s a good question Chris. The answer is pretty simple – This way is MUCH MORE exciting and gets students excited. Also illustrates the rapid release of energy, and the conversion of potassium chlorate to Potassium Chloride. Anything to get students excited 🙂
We did this but the gummy bears got stuck to the test tube. How do you prevent them from sticking to the side of the test tube?
Hi Bbosw, Glad to see you trying out the demonstration. That’s Awesome.
In terms of preventing them from sticking to the side of the test tube – if you are talking about on the way down, you want to make sure you are using a larger test tube. That will allow for it to slide down easily. Or you could use a glass rod or other long narrow object to push it down, making sure it reaches down.
If you are talking about sticking to the tube after the reaction, you can just let it soak in water for a few hours and that will make it easier to get everything out.
Hope that helps. All the best!
This is very bright and colorful and I am sure the kids will like it, but I am not sure how to tie this in with Cellular Respiration. Is it in the sugar in the gummy bear that is being oxidized in the reaction? How do you relate that to respiration? Also, how do you write out the reaction?
Hi there CT teacher. Those are great questions. In cellular respiration, Sugar (Glucose) reacts with Oxygen to form Carbon Dioxide and Water. C6H12O6 + 6O2 –> 6CO2 + 6H2O. However, that happens in multiple stages and energy is released all along the process.
This demonstration shows a similar process but instead of having it be released in stages, it releases all of the Energy quickly.
The Potassium Chlorate is used to produce the Oxygen that reacts (violently) with the Sugar in the gummy bears. The reaction that happens with the Potassium Chlorate is 2KClO3 –> 2KCl + 3O2.
Hope that helps!
Hi Leslie,
Do you have other videos with ‘cellular respiration’ material? I am particularly interested in microbial metabolism. Anything in Microbiology would be appreciated:) Thanks for the Physiology material it was very helpful.
Hi Martie,
The only other video I have covering cellular respiration specifically is found here – https://interactivebiology.com/326/. It’s kind of a general overview of cellular respiration from one of my lectures. It doesn’t deal with microbial metabolism though. Hope it helps though.
All the best!
Thanks! It was just fantastic! But I want to know, what’s the role of potassium chlorate here?
Glad you liked it. The potassium chlorate produces the oxygen that is used for the reaction. The formula is 2KClO3 –> 2KCl + 3O2.
This demonstration is awesome! I was looking for something to do with my A.P. biology class with respiration.
Thanks!
You are very much welcome. Glad you found value in it! 🙂
Am excited about this experiment can’t wait to share this with my students. Thanks Alot will let you how it worked out.
Hi, are you referring to potassium chlorate when you say “solid”?
Respiration is often confused with “breathing” which is the mechanism by which air (oxygen) is taken into the lungs (inhalation) and carbon dioxide is given off through expiration. Respiration, on the other hand, is the reaction of oxygen with glucose, fats, and sometimes protein (oxidation) to form carbon dioxide and water with the release of energy. Oxidation is a form of burning, and the same thing is occurring when any flammable material ignites. Oxygen is carried through the blood from the lungs to the cells where respiration occurs as part of the metabolic process.
Can I do this in my classroom without the hood?
I THANK YOU FOR THIS SIR. BUT THIS POINT IN TIME I HAVE SOME PROBLEMS WITH ANATOMY OF CNS, CAN YOU PLZ SEND ME NOTES ON IT IF POSSIBLE. I’M A FIRST YEAR MEDICAL STUDENT.THANK YOU FOR YOUR INTERVENTIONS TOWARDS MY DEGREE.
We have a number of articles about that hear. Just do a search above.
Nice oneeeeeeee :DDDDDDDDDDDDDD
I have a question ? I don;t quite get the partial pressure of referring to the respiratory system? P Oxygen and carbon dioxide ?
Students were impressed by the violent reaction they observed.
Thanks for the demo.
I’m love science subject but I BECAME a nurse. It’s long time ago for my turning point of life. However, I’m exciting for letting the student participation in the test 9i’m a nurse educator, that why I think about teaching method).
Thanks.
Hello Leslie,
I really enjoyed the demo on cellular respiration…it definitely is an eye opener and reveals to us the immense importance of enzymes in keeping check on the process.
Thankyou
You are a very good teacher,
thank you very much.
I enjoyed it very much, simple demo but it carries lots of scientific facts. Thanks for our enzymes that control the process WISELY and not by “all at once” :o)
Thanks for the offer.
A lot of Thanks for this presentation, SIR!
That’s way to simple for HS — we need to quantify things. Any ideas beyond what’s found in the typical Bio lab manuals?
thank you