Science Buddies: "Ask an Expert"

Hello,

I am designing a science experiment similar to the project idea, "Why aren't all medications pills?" on Science Buddies.

Here is the link:
https://www.sciencebuddies.org/science- ... ml#summary

After doing some research on insulin and gelatin, I could not find any similarities between them except for the fact that they both have a somewhat similar molecular structure and that they are both large proteins. I was just wondering why gelatin was used for this experiment, and if their are any substitutes that would yield a more accurate result?

Also, I was wondering if their are any suggestions to add to this experiment and make it a bit more complicated. (I made changes to the procedure and to the whole experiment idea.) Currently, I am going to test the gelatin in ph levels of 1 to mimic the stomach acids using HCI acids and test it with ph strips. I am also going to use the proteases solutions and sodium mixed with water to mimic the enzymes and blood respectively. I would like to keep the liquids heated to a constant temperature equivalent to the heat in our body, and I was wondering if there are any ways to do this?

Thankyou,
Student

Hello Mad_Scientist!

Cool project you've got there

Why Gelatin: This experiment is designed to use gelatin as a substitute for insulin because, like you mentioned, gelatin is a protein just like insulin is. One of the overarching points is to demonstrate the significance of proteases, enzymes that break down proteins, when thinking about why certain medications must be introduced to the bloodstream directly. Thus, choosing a protein substitute for insulin is appropriate. Although there are many other proteins available, gelatin is not only easy to find and cool to look at, but it also doesn't dissolve in water very easily. This means that when you place the gelatin in the stomach-esque environment, it might break down, but it won't be doing so because of the water. Dissolving a protein doesn't necessarily make it functionless, but breaking it down with another enzyme definitely should. gelatin's really bad solubility in water will also help keep it intact in the bloodstream-esque environment, so that if there's a difference between the two environment's effects on gelatin, the difference will be more obvious.

General Advice: Hey, those are cool ideas! Try to be VERY CAREFUL with the HCL. That's pretty acidic stuff you're working with. A good thing to do before you work with new solutions and substances is to check out their "Materials Safety Data Sheets" or MSDS for short. Here's a link to the one for HCL: http://www.sciencelab.com/msds.php?msdsId=9924285. Also, when mimicking the gastric environment I would not mix the HCL with the meat tenderizer enzymes. I don't think you were planning on doing so, but just in case. If placed in acid, although usually capable of withstanding a broad range of PHs, the meat enzymes might still get denatured and thus might not do their jobs properly for the experiment. Pepsin (the enzyme in our stomachs) can withstand the stomach climate because of its weird ability to actually get activated by the low PH...which is really cool. Here's an article on it if you're interested:http://www.madsci.org/posts/archives/20 ... .Bc.r.html

Complexity: Ok, now to the increase in complexity. How about seeing if your meat tenderizer enzymes can break down different types of proteins? We know, we know enzymes are specific when dealing with different types of molecules, but proteins are composed of the same components. So maybe you can design an experiment to see if the same enzymes can break down different types of proteins. Try isolating the white parts of a few raw eggs (don't worry, egg whites stay mostly intact in water), which contain a variety of proteins, and exposing them to your different solutions (acidic, tenderizer, bloodstream). Does this experiment display the same outcome as your gelatin protein based one? Does one seem to have been affected more than the other? Maybe you'll find another reason why mostly all protein based medications aren't ingested.

Hopefully this helped. Good luck! We'd love to hear about how your experiment turned out and if you have any more questions, feel free to ask away!

Thank you so much! I will definitely take in your advice for the complexity and general advice tips *gosh, your soooo creative!* Also, thanks for replying so quickly! I'm really starting to get excited for this science experiment!

No Problemo!! Excitement and science tend to be very compatible