We felt a re-run of the Periodic Table Cake was needed for the end of term and we were doing proteins at the time, so, slightly overambitious as it was, a protein secondary structure was in order. This one was a bit of a challenge to say the least - partly because we didn't have enough baking tins for the eleven sponges needed for the loo-roll type structure in the middle and had to keep washing and re-using them (the tins, not the sponges), partly because the "atoms" wouldn't stay on the cocktail sticks we used to skewer them together and act as bonds, and partly because we had to go to Parents' Evening - still a bit eggy and floury - in the middle of its construction. On top of the difficulties of construction there was the added problem of having to get it all right and I think I threw a number of tantrums when I stuck a nitrogen in the wrong place, hydrogen-bonded peptide links in the wrong amino acids together, or watched yet another carboxylate group plop off the cake and onto the cake board; there is traditionally a point in the construction of all our cakes when we realise it's not going to work, get all disappointed, and dejectedly eat most of the remaining icing before starting again with renewed deluded optimism, and that happened several times with this one. We did, however, end up with something plausible-looking at the end of it and I think I'd say this one was our best. It was probably a bit of a deathtrap to eat but then knowing what goes into something like this tends to put you off eating it, so we left that slightly sinister job to everyone else.