Enzymes and gelatin

This is a fun and easy experiment that demonstrated the properties of enzymes.

You need a fresh pineapple (canned with not work) with the skin removed, three bowls, and a box of Jello gelatin.

Crush the pineapple in a blender until you have a fairly smooth but pulpy mixture. Place one tablespoon of the pineapple into the first bowl labeled, "Fresh pineapple." Label a second bowl, "Heated pineapple" and set it aside.

Prepare the Jello as directed on the package. Pour it into the three bowls leaving a little room in the Heated Pineapple bowl (I needed a fourth bowl because mine were small.)

Cook the rest of the pineapple on the stove for 5 minutes, stirring constantly. It will boil, which is fine; just keep stirring it. When done add 1 tablespoon of the cooked pineapple to the bowl labeled, "Heated pineapple" and stir thoroughly.

Place the bowls in the refrigerator for 4 hours. What happened?

The bowl with the fresh pineapple did not harden into Jello while the bowl with the heated pineapple did. Pineapple contains an enzyme that breaks down protein, and gelatin is protein. Heating the enzyme destroys it allowing the Jello to harden.

Canned pineapple cannot be used because it is heated before it is canned.

This experiment will work with papaya as well. The enzyme in papaya is called papain and is so potent that it is the active ingredient in prescription debriding ointments. My Blue Goo Cracked Heel ointment I get at Walmart also has papain in it, but not for long. As of November 4, 2008 the FDA has banned papain from all over-the-counter products. I better stock up now and make sure I don't rub my eyes after applying it to my feet.

Bird Cinema

Bird-Watching meets You-Tube at Bird Cinema. You can upload your own clips or view other amateur and professional videos about birds. I find this great for matching bird sightings with bird sounds, and other informative videos are available, too. Here is one of a downey woodpecker:

More backyard finds--caterpillars

We have come across some interesting caterpillars crawling around our backyard this fall. This first one looks to be a banded tussock moth (Dasychira obliquata.) Here is what it looks like as an adult moth (not as aesthetically interesting.)

This critter is a polyphemus moth (Antheraea polyphemus.) The moth this will eventually become is enormous! We will have to keep watch for them in the coming weeks. If I find this caterpillar again we may keep it until it metamorphoses.

It just looked to us as if it were Eric Carle's inspiration for his Very Hungry Caterpillar.

Science Kits

I like to keep science kits around. My kids always enjoy the thrill of opening and using them. I like having something complete to pull out when I've had too busy of a week to plan a project. My remind my relatives that they can browse Home Science Tools around holiday or birthday times if they don't know what to get for the kids.

I often find kits for a decent price at discount resellers like T.J. Maxx or Marshall's, and warehouse stores like Costco or BJ's Wholesale Club. These are hit or miss, but usually the hits are pretty good. I am already looking, buying, and putting away for Christmas.

This photo shows ds#2 with a Sensory Dome he got for his birthday, which is a terrarium with plants that appeal to the various senses. The boys had a great time putting this together, and ds#2 in particular took keen interest in reading about the plant information on the planting tags.

Finished classification project

We finished our classification project last week. I put each collage into a sheet protector and made them our title pages for the respective sections of our nature commonplace book. Each section corresponds to a section in the Handbook of Nature Study.

I even found an online classification game that the kids had fun with. They are excited about their new knowledge and wanting to apply it whenever possible.

Curiously, I found this quote in Comstock's book:

Nature-study does not start out with classification given in books, but in the end it builds up in the child's mind a classification which is based on fundamental knowledge; it is a classification like that evolved by the first naturalists, because it is built on careful personal observation of both form and life. (p. 6)

My friend is teaching Mammal Menagerie for our co-op, a program she got from a relative that works for the public school system. It comes with a video, newspapers, and other activities. One of the first things ds#2 did was to place a list of mammals into their appropriate Orders. This did not have the same appeal at all as our basic classification activity did. The kids found it interesting, though, that our large animal encyclopedia was organized by kingdom, then phylum, then class, and then order. That made it easy to find what we were looking for and the kids had fun seeing what other mammals were in each order.

To me, that was the key take-home message--that classification is a way to group all living things and that this system is used even in the books in our home. To be required to learn the various mammal orders demonstrates the point about "book" classification, and about "stuffing facts" into kids. How much more meaningful it is to discover these things through our own observations.