Nothing is submitted. Progress saves on this device, so a second sitting picks up where the first stopped. Tap any step number to open that step; a number lights up only for a step you have finished. iPad keeps the water to 18 molecules so the simulation stays smooth on a tablet; Computer runs 120 for a denser picture.
Your record
First answers only: a prediction answered wrong and then understood is the point of the tool, not a failure. Come back another day and run the module again; the second record is the one to trust.
Real structures behind the pictures
1BAG α-Amylase from Bacillus subtilis with a sugar in its active site: an enzyme that splits starch by hydrolysis, using one water molecule per cut, just as in Module 2.
1HKG and 2YHX Yeast hexokinase without and with glucose. Put the two side by side and the cleft closes: induced fit, measured.
1UBQ Ubiquitin, a small, tightly folded protein. Colour it by hydrophobicity and the oily side chains sit inside.
molstar.org Mol* is free and open source; paste any PDB ID.
What the model simplifies: it is flat, so ice is drawn as a honeycomb with three hydrogen bonds per molecule rather than the four of real, three-dimensional ice. Molecules are drawn to scale with one another, and the hydrogen bond is about three times the length of the O–H bond, as it really is. The protein has sixteen amino acids; real enzymes have hundreds. Where a number is exaggerated so it can be seen, the step says so.