View Full Version : Biology experts! I need help.

07-18-2014, 02:38 PM
E. is taking online Honors Bio through Northwestern U's G&T program. I was going through the course today to get a list of what I needed to get for labs. We are vegetarians, and we as a family have issues with using animals in experiments (no discussion needed on this, please). I have found a way around the goldfish respiration lab, but am having issues with the pH lab.
This lab requires you to blend fresh liver and distilled h2O in a blender, test the pH, then add vinegar, etc., etc.
This will not happen in my house. I understand why the liver is used (it's a buffer), but I can't figure out what if anything can be used as a replacement for it so that he can conduct the experiment.
We will, of course, consult his instructor, but I'd like to have an acceptable alternative prepared ahead of time to present to her.
Anyone? I've googled and searched my own resource books, but I can't find anything.

07-18-2014, 03:02 PM
Is this a lab on testing catalase activity? It's been a long time since I was a bio major, so I wouldn't say I was an "expert"--not by a long shot!--but I know that cruciferous vegetables are a good source of catalase, so if that's what you're testing they might work in substitute?

07-18-2014, 04:52 PM
If it's an enzyme experiment we substituted the liver one for pineapples and jello. Not sure if jello is a no go in your house as well or if there is a vegetarian option for jello.

There's this virtual lab which may cover the same concepts. I don't know if you have the lab specifics to know whether this are viable substitutions.
McGraw-Hill Virtual Biology Lab (http://www.mhhe.com/biosci/genbio/virtual_labs_2K8/pages/EnzymeControlledReactions.html)

Good luck!

07-20-2014, 07:54 AM
Found this:

If you prefer not to use liver, lower but adequate levels of catalase may be obtained from turnips or even potatoes. To make a crude catalase solution, crush about 25 cubed cm of the turnip or potato in a mortar and pestle with about 20 mL of cold distilled water. Filter the resulting mash through 2 or 3 layers of cheesecloth, squeeze the cheesecloth gently and collect the liquid. Throw the mash and cheesecloth away. Results will show a lower rate of oxygen production with this catalase solution than with the animal liver tissue. If turnips or potatoes are used as a source of catalase, use about 100 grams of the material with 100 mL of cold, distilled water.

07-23-2014, 09:53 AM
Thanks everyone! I finally heard back from his teacher (not the best sign for this class), and she said that we could use potato. She was rather short in the email, but I am giving her the benefit of the doubt with that communication. She didn't indicate how much potato or how to prepare it, so we'll see how that goes when we get closer to the lab. Overall, I'm not impressed with the class so far, but it's early days yet. Biology is E's least favorite of the sciences, and he just wants to get it and Algebra I done so he can move on to more interesting (to him) things.

07-23-2014, 10:42 AM
GM - that sounds like my DS. He wants to do more advanced work but sighs and huffs about having to do the groundwork stuff LOL.