http://tinyurl.com/2w9p4q has the actual quote you used.
The link to ‘Fair Dealing’ on the tinyurl page also gives us this:

“Fair dealing only relates to literary, dramatic, musical, artistic and the typographical arrangement of published editions.

Fair dealing has been interpreted by the courts on a number of occasions by looking at the economic impact on the copyright owner of the use; where the economic impact is not significant, the use may count as fair dealing. So, it is probably within the scope of the above fair dealing exception to make single photocopies of short extracts of a copyright work for certain purposes, that is, non-commercial research or private study, criticism or review, reporting current events, and so on.”
(c) UK Intellectual Property Office.

“Fair dealing for criticising or review and reporting current events is allowable for any type of copyright work except a photograph as long as it is with sufficient acknowledgement” (UK Intellectual Property Office, ipo.gov.uk)

(Oh no! I’ve quoted something without permission! Sue me! Sue me!)

Anything that is published is explicitly declaring itself available for critisim and review. Publishing on a website is still publishing. If you don’t want to be quoted, DON’T PUBLISH!

Quite right! I absolutely agree with you.
So I don’t like to discuss anything with different quacks (wasted time!). However to dicuss interesting themes with clever people – it was good form even in our secondary school (I finished secondary school not in England).

I’d like to add some details to all interesting stories about photosynthesis sounded here. Explaination of crana(44) is good, but complicated a bit. He consideres that Robert Carnegie(39) knows about Photosystems I and II.
Certainly, pure chlorophyll can’t produce oxygen at all. Chloropyll can absorb the energy of light and convert it in energy of electron moving. Photosystems I and II are actually systems of donors and acceptors of electrons and protons. All these donors/acceptors are bound to specific membrane proteins (some of these proteins are donor or acceptor themselves). It is very important that all these proteins are membrane proteins (why – see below). Chlorophyll absorbs quant of light and loses the electron, which then runs from one acceptor to other one in Photosystem-II. Chlorophyll, which have lost electron, is powerful oxydizer. He takes part together with Mn-claster (twice-mentioned here) in splitting of water to oxygen, electons and hydrogen-ions. Chloropyll is reduced, taking one of these electons. Other electrons are transferred to Photosystem-I. Now it is known well, that Mn-claster requires carbon dioxide for its work. There are wonderful theories described this process and smashing hypothesis of photosynthesis evolution, which issues from these theories. See about it here:
http://www.pnas.org/cgi/content/full/98/5/2170
http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=11953312
http://www.ncbi.nlm.nih.gov/sites/entrez?Db=PubMed&Cmd=ShowDetailView&TermToSearch=11038543&ordinalpos=39&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum

Note! Molecular hydrogen is never produced in photosynthesis! Only – hydrogen-ion (proton) and atomic hydrogen. Water splitting produces protons, which can’t premeate across membrane of thylakiods and accumulate inside thylakoids, so proton gradient is created. Second way of proton gradient creation is work of Photosystems (see post of crana (44) – it is right description. Protons move from stroma to inside of thylakoid). This proton gradient itself is part of general membrane potential and is also “energy currency” like ATP (theory of Peter Mitchell)! Protons can run through specific membrane proteins from inside of thylakoids to stroma. ATP-syntase is one of this membrane protein. When proton moves across ATP-syntase, latter creates ATP. Thus process of ATP syntesis and photosynthesis are coupled by membrane. That is way I’ve said above that membrane localization is important (main!)feature of photosynthesis.
Atomic hydrogen is produced from electrons and protons in stroma and then is used for creation NADPH.
Nevertheless, Robert Carnegie is right telling about photosynthetical production of hydrogen as a fuel. Simply – in this process hydrogen is produced by specific enzyme (hydrogenase), which are in some species of photosynthetic microorgaisms. There – photosynthesis is only source of energy for hyrogenase work. Hydrogenase itself isn’t member of system of photosynthetic proteins.
Water is not only donor of protons for photosynthesis. Some photosynthetic microorganism uses hydrogen sulphide for this aim. Bacterial photosynthesis is more simple process unlike photosynthesis, which uses water and produces oxygen, because water spliting requires more energy for its realization (see my links above).
Thus – we see that oxygen can be produced only by intact complicated system of membrane proteins (plus bounded to them pigments and cofactors) and on conditions of intact membranes. If photosynthetic complexes (or membranes, where they are) are destroyed, then photosynthesis is impossible. But if they are intact, then process comes.
For example, if we cut plants into little pieces and expose them to light (better – laser!:) Labs in our institute prefer laser), then we could observe the photosynthesis in them. So if we have eaten any plants, then its piece, which still are in stomach, could photosynthesize under light action. But if we try to carry out same experiment with intestinal contents (where active photosynthetic system are absent already, are destroyed), then (alas, dear Dr. Goldacre ) we will see nothing even under laser action. Escpecially, if we will torch the bum…

*Not really knowing anything about it, for one thing.

+Until it became necessary to remedy my version, that is

“Hydrogen is liberated by “Photosystem I” but it is then taken up in “Photosystem II”, so that when photosynthesis is complete, it’s tied to glucose.”

This is, well, completely wrong. It seems like you really want to understand this – which is certainly not easy! – so I’ll try to explain the points post 40 didn’t really discuss as best I can. This explanation is certainly simplified and not all true in the absolute strictest sense, but I hope it gives you a better understanding. If something’s not clear (and I’d be surprised if any of it is) post back!

There are two stages to photosynthesis. “Stage 1″ (light-dependent) is the part that uses light, and its role is to generate several molecules needed for “stage 2″ (light-independent), which converts carbon dioxide to sugars.

“Stage 1″ of photosynthesis takes place in specialised sac-like membranes (thylakoids) within chloroplasts. Outside the sac is the stroma, inside is the lumen.

The oxygen evolving complex mentioned in post 40 essentially splits water into hydrogen ions (protons), electrons, and oxygen. The electrons are passed through a chain of several proteins; their movement is “powered” by light at photosystems II and I (named in the wrong order – II is first).

Movement of the electrons, in turn, powers movement of hydrogen ions from the stroma into the sac. This builds up a steep gradient of hydrogen ions: more inside the sac, fewer outside. The gradient is enhanced further by water-splitting in the lumen, which releases hydrogen ions. In addition, electrons that reach the end of the protein chain are combined with hydrogen ions and another molecule (NADP+) in the stroma. The resulting molecule, NADPH, is used in Stage 2 – and its formation removes hydrogen ions from the stroma, so contributes to the gradient.

The hydrogen ions naturally flow down their gradient i.e. they leave the sac and enter the stroma. They move through an enzyme and their movement supplies the energy for synthesis of ATP – the universal “energy currency” of the cell, which is needed for “Stage 2″

“Stage 2″ doesn’t need light directly, but uses ATP and NADPH from stage 1 to fix carbon dioxide into sugars.

Clear as mud? I hope I haven’t patronised anyone reading – very difficult to tread the line between patronising and utterly bamboozling…

Ouch – is that South Africa by any chance? If so I thought that woman had been given the boot and that your government had been forced in to a U-turn on that or was that just unrealistic optimism on my part?

Ouch – is that South Africa by any chance? If so I thought that woman had been given the boot and that your government had been forced in to a U-turn on that or was that just unrealistic optimism on my part?

Still, there seems to be quite a bit of confusion about photosynthesis.
Chlorophyll itself does not produce any oxygen, even when illuminated. It’s the Mn4Ca cluster of the
oxygen evolving complex that makes the oxygen and the whole process only works when all the pigments and cofactors are bound to proteins in the membrane.

Unless we acquire photosynthetic organisms or complete chloroplasts (which some animals do), we are very unlikely to function photosynthetically.

Sorry to be pedantic – but, contrary to what’s written in most text book, glucose is not a direct product of photosynthesis. Triose-phosphates (a form of sugar) are produced first and then converted into sucrose.

Anyway, this may not contribute much to the discussion here. There is no doubt that all of us are occasionally wrong about scientific issues. The important thing is that, in contrast to many of those selling nutritional supplements, scientists (or those truly interested in science) try to find out how things really work and should therefore welcome if they are challenged (instead of threatening to sue).

Of course the normal reaction converts carbon dioxide and water into glucose and oxygen.

There is always some carbon dioxide in the human bloodstream, usually carried by haemoglobin, and of course there is water.

At least one different photosynthesis involves hydrogen sulphide as one factor, but I’ll let you look that up.

I found for instance http://www.biologie.uni-hamburg.de/b-online/e24/24.htm which is not written in the best English and is a little difficult to understand, although a million times easier to read than if I myself attempted to write in German – so I say well done to the writer. “The whole carbon contained in plants is of atmospheric origin.”

Dubber’s crime was not writing anything offensive to Birch, but simply linking to an article which Birch felt promoted “hatred of the recording Industry”. Now I am aware that promoting race hate is a crime, but hatred of the recording industry? Apparently that warrants a lawsuit.

Dubber, with Birch’s permission, published the correspondence in full at http://www.newmusicstrategies.com/. You can also read the story at http://onlinejournalismblog.wordpress.com/2007/06/19/dont-like-a-blog-run-to-the-bloggers-boss/

I agree. Really – “verbal equivalent”…
Simply I think that level of our criticism against them must be high. We are scientists.

)) Superclass!! I never laughed so before! Interesting technology…;) Some questions to “inventor”. Why does hydrogen produced (what sort of hydrogen)? How do you get the light there? Why do you believe so that there will be oxygen and water? And what about hydrogen sulphide?

Dr. Goldacre, while you keep silence your colleages develope and modernize your technology. Take care! You will lose gereat patent! What about my question?

Anyway, oxygen isn’t all good, it is what you take antioxidants to stop. (At least… sort of.)

I agree (but whether it’s deliberate is another matter). It’s tempting to think of people as fraudulent if they know a lot of facts yet mix that with inaccurate claims. I think it’s more subtle in many cases: many of them just don’t get science and think it’s merely a kind of discourse style to get more authority – the verbal equivalent of putting on a white coat and lab specs. What they don’t get is that it comes with other fixtures, like being open to external checking and being open to criticism.

But it is most terrible thing when talented real scientist degrades to level of quack. Probably you didn’t see it. And I have seen!..