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Enzymes

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dr.bob
74719.  Thu Jun 15, 2006 5:17 am Reply with quote

I merely said that this was possible. I have no idea if it's actually being done, or if it has any relation to products such as Splenda.

For all I know, these products consist solely of evil chemicals that'll turn your retinas purple or something.

 
Celebaelin
74806.  Thu Jun 15, 2006 8:11 am Reply with quote

Quote:
Splenda« (Sucralose)
Sucralose is the only non-caloric sweetener made from sugar. Sucralose is derived from sugar through a multi-step patented manufacturing process that selectively substitutes three atoms of chlorine for three hydroxyl groups on the sugar molecule. This change produces a sweetener that has no calories, yet is 600 times sweeter than sucrose ( table sugar ). Sucralose tastes like sugar. It has a clean, quickly perceptible, sweet taste that does not leave an unpleasant aftertaste. The exceptional stability of sucralose allows both food manufacturers and consumers to use it virtually anywhere sugar is used, including cooking and baking.

http://www.sugarlessshop.com/2000/sweetenerinfo.htm

 
dr.bob
74863.  Thu Jun 15, 2006 10:38 am Reply with quote

Well, there you go.

I wonder why chucking in a bit of chlorine makes it 600 times sweeter than sucrose.

I guess they must cut it with something pretty bland to get the stuff you can sprinkle on your corn flakes. Hmm, I wonder what they cut it with.

 
Celebaelin
74961.  Thu Jun 15, 2006 7:19 pm Reply with quote

Enzymes are water soluble globular proteins which function as biological catalysts. They are depicted in many ways one of the most common being a ribbon diagram; a stylised representation of which is shown below with the spring-like sections representing lengths of α-helix and the arrow portions representing β-pleated sheet.



Other depictions include ball and stick, space filling and electron density map models.

A detail from an electron density map is shown below



1.6 ┼ electron density map of the active center of Bacterial Fe(III)-binding protein (FBP) from Haemophilus influenzae. The map is contoured at 2 and 9 standard deviations.

 
andrewmorris
125314.  Sat Dec 09, 2006 2:34 pm Reply with quote

Anyone know if Pepsi ever did contain the digestive enzyme pepsin? Intrestingly, Pepsi was originally called 'Brad's Drink' after its creator Caleb Bradham. Catchy.

 
suze
125349.  Sat Dec 09, 2006 5:41 pm Reply with quote

Now there's a question.

http://en.wikipedia.org/wiki/Pepsi_Cola notes that the matter is disputed, and links to citations which tell it either way.

However, http://www.sodamuseum.bigstep.com/generic.jhtml?pid=3 (a site which sells soft drinks memorabilia) states the following:

    "One of Pepsi-Cola's earliest known advertisement is found in the Feb. 25th, 1903 New Bern Daily Journal, and one of it's claims was that it "Aids Digestion" -- a popular claim for items containing pepsin. Lastly, another newspaper ad produced in 1908 flatout said 'PEPSI-Cola is an absolutely pure combination of pepsin -- that's what your stomach needs these days -- acid phosphate and the juices of fresh fruits.'"

(Spelling and grammar as original.)

There's no citation for this 1908 advertisement, but this would tend to suggest that pepsin was an ingredient, or at least that the Pepsi-Cola Company wished us to believe so.

 
Celebaelin
161843.  Sat Mar 31, 2007 7:29 am Reply with quote

suze wrote:
There's no citation for this 1908 advertisement, but this would tend to suggest that pepsin was an ingredient, or at least that the Pepsi-Cola Company wished us to believe so.

Without having done anything resembling actual checking of my suspicion I think it's unlikely that any cola drink would contain an active enzyme as all colas are about 0.3M Phosphoric Acid. Interesting question though.

 
Spinoza
161845.  Sat Mar 31, 2007 7:46 am Reply with quote

Gray wrote:
Ah, so a molecule with one 'handedness' can be converted into the other? You'd think that would be an unnecessary complication in a biological system. But then I suppose we're full of those as well. Evolution is not known for her planning ability...


It certainly isn't, but then again it doesn't know where it's going, or what might happen in the future. Evolutionary solutions to problems are selected entirely on the basis of current needs and what is possdible at the moment. Which leads to the interesting thought that if you know anything about living organisms at all, you couldn't possibly believe they were intelligently designed.

 
Spinoza
161876.  Sat Mar 31, 2007 10:14 am Reply with quote

There are 20 naturally-occurring amino acids. Proteins are made up of amino acids linked together. So if a protein is made up of 400 amino acids, there are 400 to the power of 20 possible proteins. Some proteins, of course, have a different number of amino acids, so to the total of 400 to the power of 20 you must add 399 to the power of 20, 398 to the power of 20, and so on. So there is an astronomical number of possible proteins.

Not all of this number will be biologically useful. A chain of amino acids will spontaneously coil and fold until it achieves a thermodynamically stable structure, the molecule finally taking on a morfe or less complicated shape. It is the precise details of this shape which determines the biological properties of the protein, for example whether or not it is a useful enzyme, whether or not it is a structural protein, and so on. The precise proteins possessed by a given individual is determined by the DNA in the nucleus of the cells of that individual according to a fairly simple code (the genetic code). This code is the same for all living organisms. Whatever the theoretical number of possible proteins is, it is enough for every living organism to have some proteins which are unique to that individual, unless of course it is a clone of another individual, in which case its DNA is identical with that of its clone, and the two (or more) clones have identical proteins. Typically a single cell may contain three thousand distinct proteins.

 
Jenny
161890.  Sat Mar 31, 2007 11:18 am Reply with quote

<is likewise struggling to keep up but very interested nonetheless>

So is this astronomical number of possible proteins and the individual combinations thereof the basis for DNA 'fingerprinting'?

Or have I just demonstrated my total lack of comprehension of what you were saying?

 
Spinoza
161930.  Sat Mar 31, 2007 1:38 pm Reply with quote

Jenny wrote:
<is likewise struggling to keep up but very interested nonetheless>

So is this astronomical number of possible proteins and the individual combinations thereof the basis for DNA 'fingerprinting'?

Or have I just demonstrated my total lack of comprehension of what you were saying?


Precisely. Every protein is coded for by a sequence oF DNA. Although a great deal of an individual's DNA is common with that of other individuals, indeed with that of the entire anikmal kingdom, each of us has bits of DNA which is unique to us. Further, under the right conditions that DNA can replicate itself over and over again, in a test tube, so enough can be obtained to analyse it and compare it with a sample of DNA from you, such as a swab from inside your cheek. So if you are careless enough to leave a hair or a single skin cell or a tiny trace of body fluid somewhere you oughtn't, e.g. on a murder weapon, the fact that it is you and nobody else who touched it will be discovered by our friendly forensics expert.

 
samivel
162098.  Sun Apr 01, 2007 11:56 am Reply with quote

Unless you live in Scotland...

http://news.scotsman.com/topics.cfm?tid=1385

 
Spinoza
162102.  Sun Apr 01, 2007 12:08 pm Reply with quote

samivel wrote:
Unless you live in Scotland...

http://news.scotsman.com/topics.cfm?tid=1385


This case seems to relate to conventional fingerprints rather than to genetic "fingerprints", but it's worth considering that genetic fingerprints aren't infallible. Particular concern must be that since the polymerase chain reaction through which the sample DNA replicates will cause any DNA present on the sample to replicate many times over, meticulous care is required to prevent the sample DNA being contaminated, for example by an operative or police representative coughing over the scene of the crime.

 
Jenny
162119.  Sun Apr 01, 2007 1:10 pm Reply with quote

Yes, that's an interesting issue. The problem is that many non-scientists want to have this image of science as 'infallible', and when a scientist, in his scientifically-trained manner, carefully points out potential flaws in the research or the argument, at least some members of Joe Public go 'Oh well 'sall bollocks then innit?' and go off and believe any old crap that somebody with a convincing website can sell them. So any day now I expect to see the Daily Mail with a large headline about how you can't trust DNA evidence.

 
Spinoza
162123.  Sun Apr 01, 2007 1:17 pm Reply with quote

You can, provided that at every stage it's handled properly and with meticulous attention to the precautions it needs. I'm not sure that when the present rather authoritarian government or one of its successors gets its way and has everybody's DNA on one of its crappy computers, we won't be hearing of appalling cock-ups and injustices.

 

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