Acid blood edit
PLAYBACK C/ cont// ref 11:56:58 edit
(pg. 139)
"Excuse me - How do we know this stuff to be blood? As far as we know the creature could carry the stuff in its skin capillaries or an acid sac purely as a defensive measure. There's no implication from the account here that it is actually a blood medium"
"You're right, it is an assumption and we can't leave out the possibility that it may use another fluid for blood."
"Micheal, we have a working theory at the moment that the alien creatures' physiology may be based around fluorocarbons and hydrofluorocarbons. The blood itself may be a compound based on fluorines; maybe a working medium medium based around hydrofluoric acid..."
"-Shoot! That's evil stuff! Splash some of that stuff on your hand and your best cure is to cut off your arm at the shoulder before it works its way up through the capillaries and the nervous system to the brain!"
(pg. 140)
"What stops that - nothing right? It dissolves glass, steel, any hydrocarbon polymer-"
"-You can't stop it. The only things it won't touch are fluorine compounds-"
"-PTFE-"
"-Polytetrafluoroethanes, teflon, whatever."
"Well, that would explain why it ate through the hull. If it was a fluorine-based lifeform it wouldn't need any oxygen at all to convert energy - when the adult form eats, its digestive system would snip-up all the long-chain molecules, throw out the oxygen as waste and manufacture fluorocarbons and chlorofluorocarbons-"
"-Assuming this hypothesis is correct; the adult form would operate just like those breeds of insects which use their blood to digest their food-"
"-Jesus H. Hubbard! That's damned efficient!"
"Hold it, but what about the polysaccharide tegument? That would indicates a structure around carbohydrates - some kind of chitin or glucosaminoglycan. Assuming Ash's analysis was correct, this is a hydrocarbon based life form. Any fluorine-based medium would dissolve it-"
PLAYBACK C/ cont// ref 12:16:48 edit
(pg. 140)
"So, if we hypothesize that the alien blood is fluorine-based, when it eats a human, it would extract mainly carbon compounds, along with the fluorine components it needs to manufacture the saturated fluorine compounds-"
(pg. 141)
"-Rumiko, I'm still having problems working out all the enzyme kinetics needed for these theoretical fluorine-based enzymes to convert a hydrocarbon based mass into usable energy. I'm sorry, I'm not convinced that this hypothesis stands up. We know the teguement of the parasite has a hydrocarbon base. What other molecular acid options are there for a blood medium?"
PLAYBACK C/ cont// ref 12:19:35 edit
(pg. 141)
"It could work as a hydrofluoric/hydrochloric mix. The preferred concentration in the blood is HF. However an embryo implanted in a human body would have access to the ready supply of HCL from the hosts stomach. It starts life with an HCL imbalance which could alter as it grows. Of course, it could take on additional chlorine and fluorine from its prey, or it could 'salt' it with sodium chloride or sodium fluoride."
"Sorry, this model is just too elaborate for my tastes. I still don't buy it. Even with PTFE coated cell membranes, wouldn't the body chemistry of a fluorine-based embryo be so hostile that it would just eat through the linings of the hosts body?"
PLAYBACK C/ cont// ref 12:45:01 edit
"I wouldn't like to touch one of those suckers!"
"Hmm?"
"If Rumiko's theory is right, the alien blood could be highly reactive to fire. But think - if one goes up in flames, releasing all those hydrofluorocarbons, then BOOM! Your ozone layer goes to Hell! Heh! -"
PLAYBACK C/ cont// ref 13:22:51 edit
(pg. 141)
"Sorry Rumiko, I still can't get the chemistry to work. What other options are there that fit the data. Assuming, that is, Ripley's account is accurate. Do we know for sure this stuff ate through the hull? Was it really a blood spurt or could the parasite have spat it from a sac or gland?"
PLAYBACK C/ cont// ref 13:29:20 edit
(pg. 142)
"We have another working possibility based around a hydrocarbon structure. This assumes that the acid compound works slower then described. The blood consists of sulphate and nitrate groups and would probably - as in the earlier model - aid directly in food digestion. This would allow it to extract protiens from its prey easier then in the fluorine-based model - though the creature would require an atmosphere with at least some free oxygen. This doesn't quite square with the observed conditions on the pre-terraformed LV426. One whacked-out idea completely out of the left-field has the acids acting as a bio-electric battery. This way, the creature would need no oxygen at all; unfortunately we've not yet hypothesized a mechanism for replenishing or 'recharging' the battery."