Posts Tagged ‘RNA’

OnScreen Gene Transcription Shows How DNA Works

Friday, February 10th, 2012

It took longer than I thought it would (no surprise there), but the second installment  of a projected three-app suite to teach the structure and function of DNA has been approved by Apple for placement on the iTunes App Store. The title of the app is OnScreen Gene Transcription, and it’s for iPad only.

mrna construction

Here’s the app description:

What good is DNA, anyway? OnScreen Gene Transcription uses engaging animations with a virtual double helix model to make clear and memorable how a recipe for a protein stored in a DNA gene sequence is made available for use by being copied nucleotide by nucleotide in the construction of a messenger RNA molecule. Students from middle school on up can learn from the app, as no advanced knowledge of chemistry is assumed. The model is exactly the same as the one found in OnScreen DNA Model, a companion app that teaches the structural details of DNA.

The sequence of events in gene transcription unfold in three-dimensional simulations that don’t skip over the need for unwinding the DNA after the strands have been separated. The formation of a hybrid DNA-RNA double helix during RNA construction is correctly shown instead of the two-dimensional ladder structure sometimes depicted. Important details about transcription that are often given short shrift or omitted altogether, such as the essential role the enzyme pyrophosphatase plays in the cell, are included.

Set the simulation to pause after each new significant step or pause it only when you want. Commentary on what is happening is literally at your fingertip in a popover. Rotate, translate, or zoom the model during the simulated transcription for a better view just by finger slide gestures. Background material on DNA and RNA are found in the Useful Stuff popover.

The ball-and-stick model has the advantage of clarity at the expense of atomic detail. The RNA Polymerase enzyme complex, while not shown in the view with the DNA model, so as not to obscure what is happening with bonds and strands, is depicted in the Sequence View below the model, thus making the point that it moves along the DNA, as it initiates and controls the reactions in transcription. We know of no other simulation of gene transcription on the internet or anywhere else that shows what happens as thoroughly as OnScreen Gene Transcription does.

Following the lead of its companion app, OnScreen DNA Model, the new app includes a Useful Stuff popover (hidden unless summoned) with several items, some of which are extensions of those found in the earlier app with mention of how a feature of DNA also is found somewhat modified in RNA and others that are specifically on topics of gene transcription. An example of a Useful Stuff item can be seen in the screen shot below.

useful stuff popover

The Mac and Windows software (OnScreen DNA) which inspired the iPad apps makes use of a tutorial format, with comments for before and after steps in the simulations displayed in a small window that is always visible to explain what is happening. There’s not room for this on the iPad, but the commentary on the gene transcription steps is available in a popover, hidden from view until the Commentary button is tapped and then hidden again by a tap anywhere else on the screen.

transcription commentary

OnScreen Gene Transcription joins OnScreen DNA Model in the Medical category on the app store, since Apple hasn’t yet realized the need to have a Science category. The Nobel Prize for Medicine usually goes to biologists, so it’s not terribly miscategorized, I guess. Since it is an educational app, why don’t I put it in the Education category? It’s mainly because that category is swamped by toddler and early learning apps, and the chance for visibility is very small unless an app is somehow featured. Anyone deliberately searching for a DNA app through the App Store keyword search will find the app not matter what category it’s in.

I was pleasantly surprised and gratified to see that someone at Apple had recognized OnScreen DNA Model was a biology education app and had seen fit to put it in the featured Life Sciences: General Biology section of the iPad Education category that turns up on the iTunes App Store, desktop version. It has definitely helped sales. OnScreen DNA Model is my top selling app, and the Mac version is doing relatively well too. I’m hoping to see OnScreen Gene Transcription appear in the same featured section as OnScreen DNA Model. Unfortunately that would seem to mean another app would have to be bumped, if the limit is twelve per section. I could give Apple a hint that any app that shows DNA as a left-handed double helix in one of its screen shots shouldn’t be featured, which would take care of that problem. It is not OnScreen DNA Model that makes that basic error.