David W. Lawlor

I rarely give up on a book. Don't quite know why....but something about finishing job once you start on it. But in this case I've decided to give up when I'm about half way through. Two reasons really. The first is that .......despite a reasonably background in chemistry and biochemistry and some years working with the processes of photosynthesis.....the subject matter is just so complex and Lawlor doesn't seem to make things easier. the second reason....which is probably a bit more telling is that the book is now 30 years old and a huge amount about photosynthesis has been elucidated since then and new techniques are available...or more widely available. So the chemistry is really out of date. And a lot of the hypotheses that Lawlor puts forward haver probably now been either proved or disproved.
Another factor in my decision to give up is the lack of colour in the book which modern texts in biochemistry , more or less, take for granted and it is enormously helpful in understanding complex molecules.
Have I learned anything from the book. Well yes. I had never really focused on it before but Lawlor draws attention to the fact that photosynthesis in all organisms conforms to: donor + acceptor reacting under the influence of light in the presence of pigment and the necessary mechanism. It doesn't just mean chlorophyll based photosynthesis with the consumption of carbon dioxide and production of oxygen.
So with the prokaryotes (without a nucleus enclosed in a membrane) there are anoxic forms such as purple sulphur bacteria and green sulphur bacteria ...where the source of the reductant can be hydrogen sulphide, hydrogen thiosulphate, hydrogen...or gaseous nitrogen). And there are Oxygenic forms such as blue green algae which evolve Oxygen. the source of reductant is water and they can reduce gaseous nitrogen.
And with the Eukaryotes ....mainly multicellular organisms where the cell nucleus is in a membrane ....there are NO Anoxygenic forms. Examples are green and red algae, higher plants such as the bryophytes and angiosperms. These evolve oxygen and use water as a source of reductant. They do not reduce gaseous nitrogen.
He also includes a number of useful and interesting tables such as Table 4.1 which is a semi quantitative analysis of the photosynthetic system in an 'average' C3 plant. I do remember asking the resident Chemist in the CSIRO lab where I was working if he could analyse some leaf samples that I had and measure the chlorophyll content. Unfortunately, that just showed my ignorance because he asked me (quite reasonably, "what sort of Chorophyll"...so I was sent back to the books to educate myself about the multiple varieties of chlorophyll. And maybe my adoption of this book is still me trying to work through that ignorance.
Probably it was a useful book for somebody working on photosynthesis in the late 1980's but it's just hard going for me at the moment. And dated. I'm giving it three stars but would recommend a more recent text book for anyone seriously interested in Photosynthesis.… (meer)