Theophrastus

That's interesting. Why so? If I'm not mistaken, three A's code for a lysine residue. Why do eukryotic proteins show a greater tendency to form numerous consecutive lysine residues?

A, is simply an abbreviation for adenine, one of the four bases, in RNA (adenine (A), Cytosine ©, Guanine (G) and (U) Uracil). As for the 3' (3 prime) and 5' (5 prime) (given the first, you should be familiar with the second), these define the direction of the RNA strand. 3', is the hydroxyl group, bonded to the third (or gamma) carbon of the ribose sugar, that lies at one end of the chain, while 5' is the hydroxyl group, bonded to the 5th (or epsilon) carbon of the ribose sugar, at the opposite end of the chain. This has particular relevance in DNA which has two antiparallel strands, and thus defines, the strand's direction, and in doing so, its identity. (Here's a link showing a dinucleotide; it's nice to have visuals ) http://journals.iucr.org/c/issues/2005/08/00/hj1051/hj1051scheme1.gif So, finally what this means is that the first several nucleotides, moving from the 3' end, are AMP (adenosine monophosphate)

In terms of cancer treatment key diagnostic testing and the like, you are right Pangloss, that Canada has and is still having a lot of trouble, (I know, quite an understatement) in the past 2-3 years, with numerous people still waiting for things as simple as diagnostic tests, and even more serious matters of treatment. Why you ask? Well, in response, I have two words: Chalk River. It's mostly because our primary source of radioisotopes for medical use, (by our, I mean that of Canadian hospitals, and the medical community in Canada) was Chalk River Reactor, in Ontario, northwest of Ottawa, however, not long ago, there was a radioactive leak. The reactor in turn got a lot of negative publicity from environmentalists, and was closed down, for maintenance, as a result. This radioisotope shortage has left many patients without the opportunity of treatment. This problem was constantly featured on CBC last year, and I admit that for many people waiting for diagnosis, and treatment, this has been a very difficult time. I have heard however, that in goodwill, some universities, have been using their equipment, to try and produce small quantities of these radioisotopes, for patients' to use, however, certainly this remains a serious problem, in Canada, for the treatment of numerous "lifelong" diseases. I see what you're going at, but this is not so much a problem of the system, but more of circumstance. I suppose that systematically, such a thing could have been avoided by diversifying our source of radioisotopes, importing from other countries like Holland and France, in case of a leak (while this would likely lead to higher costs; with all things, there are pros and cons). It is true that there are problems in the Canadian system; it is not flawless, but as for the model itself, there can be no denying, it has potential, and is able to cover everyone, and still pay for it, by making your payment indirect.

Actually, that sounds a lot like something Obama said during the "Three Amigos Meet" in Mexico, in response to some questioning .

lovely. Thanks for the help. By the way, how'ld you make those images? Do you have some sort of custom program, to model structural formulas and whatnot? It could be damned useful to be honest (implying its taken on the free economy model in one way or another; I don't have much money to spend).

Hey, out of interest, does anyone know of any science- related contests/ competitions (particularly in chemistry, biology, biochemistry, invention or general sciences(theoretical and experimental)) that a Canadian high school student can participate in? (Whether national or international (or municipal, if it's one of the larger cities ie. Ottawa, Montreal, Toronto, Vancouver) While I have specified some of my preferences I'm pretty open to anything that can be found. Thanks in advance, -theo ps: Age isn't an issue either, as I only begin next year, so I'm open to a rather broad spectrum.

Well yeah, water would screw with yield, resulting in some incompletion, and thus acetone formation, but I suppose the reaction will still occur to a reasonable extent, right? [edit] Damn, I just thought of something, incompletion would mean there is an equilibrium present. $@! That could be screwy, very screwy. As for aldol condensation, yeah, I failed in that respect, though out of interest, what sort of factors determine, whether the shift will occur? [edit] Nevermind, I just looked at the structural formulas of acetaldehyde and formaldehyde. If it is so, wouldn't propionaldehyde, be able to participate in the canizzaro reaction?

Thanks for the clarification UC.

Ah, nothing but a slight reading error- you missed the part where I said to simplify the molecule, cutting all the "R" groups, this would have cut some double bonds, and formed others, to result in eleven. Wait, hold on... doesn't haem have 13 double bonds? Well, everything does, techniquely. Factoring out "delta G o" (sorry, I don't know how to latex that), and product/ reactant molarity shifting to conc., the result has no dependence on the gradient involved, and is determined solely by concentration ratio, and temperature. That's why I added the bit with adding calcium's atomic number to it. Otherwise you could skip a multitude of preceding steps.

yup. Your turn UC! ps: Oh yeah, and in terms of air holder, I was refering to the latin/ greek (can't quite remember which) derivation, of the word artery. Red blood cells are suspended in the blood, and the oxygen- carrying protein in them, haemoglobin, has four haem groups, which are essentially porphyrin derivatives.

Not quite. You see, this is what happens, the potassium hydroxide donates a hydroxyl group to the aldehyde, as such, the bond structure of the aldehyde shifts, and the oxygen that was formerly double bonded, is only single bonded, due to the bonding of the OH. As such, the oxygen is negatively charged. By nature, this configuration, as an end product is unstable, and this intermediary gives off an oxygen, to oxidise present aldehyde, generating a carboxylic acid, while the first aldehyde/ former intermediary, having lost an oxygen, and gained a hydroxyl group, is now an alcohol. Furthermore, given the basic environment, the potassium hydroxide, reacts with the acid, to form sodium acetate. I understand the confusion; it is a bit of a non- standard reaction really. Here's a link with pretty pictures, which I think would greatly help... http://en.wikipedia.org/wiki/Cannizzaro_reaction

And lo, having finally attained computer access, Theo prepares to piss off the general populace, with this next question! Enjoy So, here goes The following class of compounds, contain nitrogen, carbon and hydrogen.They have a ring structure and are ligands, primarilly forming complexes with 2+ and 3+ metal ions. When bound to calcium, they form pigments, that are bright purple in colouration, and utilised by some molluscs. In the human body, a particular type of this compound is found in cells, suspended in a fluid, found within the "air holder," only bound to protein chains. (hint: In reading this post, you are likely looking at it(Theo motions to the upper right hand corner )) (Theo's dirty double trick ) Take the compound you have just found, and make it as simple as possible (all R groups = H) count the number of double bonds, present. (ps: no funny business like exploiting double bonds to halogenate the molecule in question ) Take the number you have attained, and add nine. This the atomic number, of a corresponding element. (Even more you say ) Now calculate the energy (KJ mol^-1) required to transport this element's ion across a cell membrane, (uniport system only) at 309.6K (36.6 degrees celsius- standard physiological temperature), given an internal ion concentration, 10 times greater than the external ion concentration. Now take the number you have just attained, and round it to the nearest whole number. Now add this number, to the atomic number of the ion gradient from before. The resultant number, is the atomic number of the element to which I refer. Solve it! Solve it if you can!!! *insert evil laugh here* Muahahahahahahahaha!

Disilanyl Alcohol (I'm not quite sure if that's the name, nut it's basically the silicon analogue of ethanol) ? Or maybe your hinting towards silicon itself? I think I've just confused myself well enough.

Gallium right? As Paris, France is the city of lights, and Gallium is named after the old word for France: Gaul.

Yeah, I suppose. I can admit that a similar thing occured in the thought process regarding my own selection. Shame...

Alas, it's the last day, and only six nominations? What's with the lack of participation?

Given this persistent skepticism, I'm going to attempt to clear things up, by setting some basic examples. Your first problem, Bob (I would address dr432, but he has sadly disappeared- (gasp ) the magic of moderation!) is that you believe that hydrogen peroxide, takes purely the role of an oxidiser, within a reaction, decomposing, and thus donating an oxygen atom to the reaction. Thus why when combined with sodium hypochlorite, produces oxygen gas, in this reaction: [ce] H2O2 + NaOCl -> H2O + NaCl + O2 [/ce] To explain, why my second proposed pathway is taken, I'll begin with an example: bubbling chlorine gas through hydrogen peroxide. Based upon your hypothesis, the peroxide will eject its oxygens, and the products will be oxygen gas, and hydrochloric acid: [ce] H2O2 + Cl2 -> 2HCl + O2 [/ce] If you are slightly more conservative, in your point, you might say that the chlorine will simply react with the aqueous medium, to form hypochlorous and hydrochloric acid, while the peroxide simply naturally decomposes: [ce] 2H2O2 -> H2O + O2 [/ce] [ce] H2O + Cl2 -> HCl + HOCl [/ce] In regards to my first incorrect example, this reaction is definitely not the prevalent one, however, my second one is none more so, as it assumes (based upon your assumption) that the hydrogen peroxide is purely a bystander, and while the reaction with chlorine and water, will occur, the peroxide also partakes in the reaction. Why, you may ask? Due to the instability of the central oxygen to oxygen bond, the reaction will instead progress as so: [ce] H2O2 + Cl2 -> 2HOCl [/ce] This is the reason why this reaction will occur alongside the generation of oxygen gas; the breaking apart of hydrogen peroxide's central oxygen bond, to form hydroxyl- esque radicals. This is why, alongside the one I displayed above, this reaction will occur: [ce] H2O2 + 2NaOCl -> 2NaOH + O2 + Cl2 [/ce] (Cheers?). Oh? and FYI, in regards to your post on hypochlorous acid, you should note that hypochlorous acid is an oxidiser, as well as an acid (just like [ce] HNO3 [/ce]), and as such will naturally, with exposure to light or heat, decompose to oxygen, and [ce] HCl [/ce]. This [ce] HCl [/ce] product can then react with present [ce] HOCl [/ce], to form chlorine gas. While the equimolar quantities of [ce] HCl [/ce] make the reaction run 'til completion, its not necessary, in order to make a solution of [ce] HOCl [/ce] produce chlorine gas. [ce] 2HOCl -> 2HCl + O2 [/ce] Finally, to the OP, Saturnine, I apologise for all this irrelevant argument, however for practicality's sake you should probably just use John Cuthbert's method, which is, all that is required of it- it's simple and effective.

Thanks Cap'n, all better now!

Aw damn, she beat me to it . I'm annoyed, personally. I don't really see what relevance copernicus has with chemistry. I was rooting for Paulinium, after Linus Pauling, though they might confuse the namesake, with Pauli- that could get rather screwy. How about nYdoaPsium. (not-your-dad-on-a-pogo-stick). (sorry, I couldn't resist )

Odd, it still doesn't seem to work for me; when ever I press on organic chemistry, I attain: Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 524288 bytes) in /www/scienceforums.net/html/forum/includes/functions.php on line 243 Odd, very odd....

I never meant that the production of chlorine gas, would have higher prevalence over that of oxygen, however, if you believe it shall only occur in insignificantly trace amounts, you are sadly mistaken. I recommend you read this' date=' particularly in regards to the section covering inhalation/ ingestion: http://msds.chem.ox.ac.uk/CH/chlorine.html If you are refering to the direction of the arrow' date=' I believe you are confusing this with the following reaction, involved in sodium hypochlorite's initial production: [ce'] 2NaOH + Cl2 -> NaOCl + NaCl + H2O [/ce] Thanks Insane Alien; I second that notion.

Well yeah, you're right, but I highly doubt that enough chlorine would be produced, in order to get the necessary high concentrations, to give it a visible, pale greenish- yellow tinge. In making my statement, I was speaking with pragmaticism in mind.

Hey guys, I'm using a bit of an outdated textbook, so I'ld like a little help on this. What is science's current viewpoint on the structure of the phylogenetic tree for prokaryotes, in terms of what came first, and then with consequent evolutionary changes, what followed? If anyone can give me a good visual, that would be really great (As that's primarily what I'm looking for; I'll discern the rest accordingly). If not, if someone could give me the basic structure, verbally or by means of a link, that would be great. It's for some research I'm doing into the evolution of prokaryote metabolism. Any help would be greatly appreciated Cheers! ps: If anyone also knows whether certain sections, in terms of chronology, are the topic of dispute, that would also be great to know.

"...It looked like pure oxygen..." -I should note that both gases are colourless' date=' and thus, you cannot expect to be able to visually distinguish between them. No smell of chlorine? You actually went on to smell the gases produced, knowing the possibility of chlorine gas present? That's quite tactless. I assure you, there are far better ways to test for chlorine, than breathing its vapours. (Which by the way, in case you didn't initially know, are [b']toxic[/b]!) I recommend you don't do something so foolish as smelling unkown gaseous products, unless you desire to suffer from associated health problems. Consider that the initial purpose of this method, was to neutralize any bleach, present on ones hands. Please re- evaluate your statement accordingly. The reaction itself, is non- stoichiometric, taking two (or more) pathways simultaneously: (In this case it's 2, if you don't count the independent decomposition, of the two oxidisers) [ce] 2NaOCl + H2O2 -> 2NaOH + O2 +Cl2 [/ce] [ce] NaOCl + H2O2 -> NaCl + O2 + H2O [/ce] I believe the first reaction pathway I noted, was the one UC was refering to.