Science Buddies: "Ask an Expert"

I had a problem with my experiment. Almost all of my supplies did not work. I bought 2 bottles of invertase, 3 bottles of glucose test strips, and used more glucose tablets then I should have. I don't know if there is something that I missed or, if I am doing wrong. If you could tell me what to do then it would be greatly appreciated


Thanks!!!!!!!!!

Hi ldboazman,

Based on your post, it sounds like you know you made a mistake when you did the project (i.e., didn't follow the procedure exactly). Is that correct? If you know that you skipped a step or made a mistake on a step of the procedure, then the best thing to do is to redo the experiment, making sure you follow the procedure exactly and don't skip any steps, add wrong amounts of things, etc. If you didn't make a mistake the first time, post back with more details about what the problem is. Right now there isn't enough information for me to figure out what might have gone wrong.

I didn't miss any steps. Sorry I wasn't clear in my post. I am having a problem getting the invertase to react to the room tempreture foods. I have use 3 different test strips and all of them work because I tested them. My mom purchased the invertase twice just to be sure we didn't have a bad bottle. The invertase didn't work with the 15 mL of sucrose either. I am not sure what I am doing wrong. My project is due on 10/31 and I am getting a little discouraged.

Hi ldboazman,

Thank you for these additional details! They are very helpful, but I still some more details to understand where the problem is. Post back with the details, and I'll answer quickly so that we can get this project completed on time!

So, you tested your glucose strips as it says in the "Testing the Glucose Strips" part of the procedure, and those test show that the glucose strips are working, correct? The colors all matched what they should be for the particular concentration of each solution? And the glucose test strips also gave you reasonable results when you tested the glucose concentration in the foods before adding invertase?

When you did the test with glucose under the "Testing Invertase Activity" heading, you didn't see any change in the glucose level with time, correct? Did the test strips give a glucose reading of 0 (i.e., were they the same color as the negative control test)? Or were they all giving a non-zero reading? Did the test strips change color at all during the "testing invertase activity" part of the procedure? Were you storing the invertase in the fridge?