In article <C7Du7y.KB7 at compsci.liverpool.ac.uk> rcp at csc.liv.ac.uk (Raymond C. Paton) writes:
>>>I am at the stage of developing some
>models of the Light Stage of photosynthesis
>which reflect computational activities in
>this process.
>>The source for the model is basically a
>Scientific American article by Hinckle
>and McCarty: How Cells make ATP.
>I have used this because it illustrates the
>process of non-cyclic photophosphorylation
>very well for our purposes. However, I am
>conscious that it may be somewhat out of data
>and there are certain issues it does not address.
>>Can anyone help with the following:
>>1 Are there more recent models of the process ?
>>2 How are the molecules in the membrane organised
>in space and how does this organisation change with time ?
>>3 Has any work been done on discrete models of
>non-cyclic photophosphorylation or related processes ?
>>Any help will be greatly appreciated.
>>Ray Paton
>>>Dr Ray Paton
>Department of Computer Science
>The University of Liverpool
>Liverpool L69 3BX
>UK
>>Email: r.c.paton at csc.liv.ac.uk>>>>
To: rcp at csc.liv.ac.uk
Subject: Re: Computer models of light stage
Newsgroups: bionet.photosynthesis
In-Reply-To: <C7Du7y.KB7 at compsci.liverpool.ac.uk>
Organization: Keele University, England
Cc:
Bcc:
Dear Ray,
In answer to your questions, it depends what you are trying to model.
We have used the basic Hinckle/McCarty description to model ATP
synthesis by isolated thylakoids quite recently, see:-
QUICK AND MILLS BIOCHIM BIOPHYS ACTA (1988) 932, 232-239
That model explained the rate of ATP synthesis, proton fluxes, and
electron transport rates quite well, but was based on delocalised
chemiosmotic mechanisms and treated the electron transport and ATPase
complexes very much as black boxes.
If you want to model the electron transport process itself (i.e.
kinetics) then you need more information on the complexes themselves.
The latest thinking is that PSII is in the appressed regions of the
grana whilst PS1 and the ATP synthase are in the stromal lamellae and
fringes of the granal stacks. Many workers believe there are membrane
located proton "tracks" running between proton producers and consumers
- this would add great complexity to any model.
At a more physical level, light harvesting and transfer of absorbed
excitation energy between pigments has been extensively modelled
over the years - Jonathon Marder would know more about this than me.
If you want more info drop me a message detailing what it is you are
trying to model.
I am also involved in a TLTP initiative which aims to produce and
disseminate TEACHING software in this area. I had given some though
to producing something on the light reactions. If you would like to
collaborate, let me know - there are some strings:
- any software must be usable under WINDOWS 3 (though it could
be launched from an authoring package such as ASYMETRIX TOOLBOOK
- the software must be in the public domain
Best Wishes
John Mills
---------------------------------------------------------
Dr John Mills tel 0782 621111 ex 7104
Dept Biological Sciences fax 0782 630007
Keele University,
Staffs ST5 5BG eml bia02 at seq1.keele.ac.uk
---------------------------------------------------------
