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Lego is in our DNA

What can you do at home on a rainy Saturday afternoon for less than $15 that captures the imagination of a a four- and seven-year old and their Dad too?

The kids might suggest sitting on the couch and watching all three Harry Potter DVDs.

But one recent weekend this Dad had other plans. I had saved up a project, and we had enough free time. It was time to do some Lego microbiology.

Eric Harshbarger

A few weeks ago while browsing Eric Harshbarger's Lego sculpture website (which includes many amazing creations, including incredible Lego globes, ginormous and clever mosaics, and a full-scale working Lego grandfather clock), I came across his wonderful Miniature LEGO DNA.

A model as beautiful and elegant as this can inspire only one thought in any Lego maniac:

"Wow, I gotta build one of those!"

BrickLink

Where do you get all the special bricks to build something like a Lego DNA? You go to the Ebay of the Lego world, of course: BrickLink. The BrickLink website is a phenomenon to behold. It brings together more than two thousand Lego nuts around the planet who have set up a store to sell you their kits or individual pieces, new or used. Every one of the 44,278,056 items on sale, from the most collectible ancient Lego set to the tiniest 1x1 flat Lego plate is carefully catalogued, counted, and priced. It is all amazingly unofficial, hobbyist-driven, and friendly. And (in a good Lego-nut kind of way) it is all a little bit insane, when you think about it!

For the Lego DNA, we would need 40 2x1 red technic bricks, 80 transparent 1x1 cylinders in four different colors, 20 gray technic pins (without friction), a nice round 8x8 plate, and four modified 2x1 plates to stick on a 2x8 plate. While I was shopping, I picked up a few other cool pieces. (And who can resist picking up cool pieces you see even when you don't need them? I had no idea what I'd use "6 x 6 x 10 Stanchions" for, but they ended up coming in very handy in a different project soon enough.) The whole tab? South of $15, postage included.

The pieces arrived very quickly and then sat in their shipping box, waiting for some free time.

So when the rainy Saturday arrived and the kids were itching for an activity after lunch, I emptied the little box of Lego on our dining table. All the colorful pieces had been packed nicely in tiny ziploc bags, and Piper and Anthony wanted to open them up to play.

Alrighty!

DNA is Child's Play

The nice thing about making Lego DNA with small kids is that it is a very repetitive and simple model. I made a few base pairs together with Piper, who is four, and she had a pretty easy time building a bunch more herself.

The main issue was to make sure preschool Piper had a chance to build her share before second-grade Anthony used up all the pieces.

But there are certainly a few things that can make you stop to think about DNA along the way, even when you are an impatient second grader. Both kids were pretty happy to see how red "adenine" and yellow "thymine" bases were always supposed to pair up, and that blue "cytosine" and green "guanine" pieces went with each other. "Don't mix them up," Piper said to Anthony several times. "I know, I know, hand me over some more of the yellow ones..."

Promoting Transcription

After they knew that the cylinders were "bases", they wanted to know what all the other Lego pieces stood for. So they learned that the red blocks made "phosphate chains" and the gray pins were "hydrogen bonds." Just words. But kids love to know the names of everything.

It was pretty clear to Anthony that the stack of colors were "like a code." So we coded up a TATAAA box to get things started. (I wonder if he will remember that sequence when he grows up!) And then they imagined the spiral going on and on forever in "real" DNA, and how it might unwind and unzip to replicate.

The phosphate chains in our Lego model unlinked much too easily: in real DNA, the hydrogen bonds are supposed to be the weak links, and the phosphates are supposed to be strong, but in Lego physics it was the other way around. So there was quite a bit of recombination during construction. But that didn't seem to discourage Anthony, who persisted in squeezing the phosphates of our Lego DNA together until we had all 20 base pairs stacked up in a nice double helix.

Very pretty. Voila!

Okay, Movies Too

By the way, if your second grader wants to know what DNA is really for, it can't hurt to sit on the sofa and watch some movies. Here is a good one.

There also are some amazing ribosome movies like the last one here that scientists have been making over the last few years. Understanding of the exact chemistry of transcription/translation/etc continues to improve every year, so when the kids grow up, these movies will look like clumsy approximations. But there's no doubt that the real-molecular-structure movies they can already make today are pretty neat.

Posted by David at February 9, 2006 09:53 PM