Shedding light on nature's nanoscale control of solar energy

Apr 18, 2012
A schematic of the Rhodobacter sphaerodes hexameric core, featuring the "special pair" (P) of degenerate bacteriochlorophyll (BChl) molecules, and the active (a) and inactive (b) arms of BChl and bacteriopheophytin (BPh) molecules. The transient absorption (ΔA) spectra acquired following selective excitation of P are shown.

Nature's process for storing solar energy occurs in light-absorbing protein complexes called photosynthetic reaction centers (RCs). Across billions of years of evolution, Nature has retained a common light-absorbing hexameric cofactor core for carrying out the very first chemical reaction of photosynthesis, the light-induced electron transfer across approximately 3 nm. This process has direct analogies to light-driven charge separation in photovoltaic devices.

A team of users from the Notre Dame Radiation Laboratory and Argonne's Chemical Sciences & Engineering Division working with the Center for Nanoscale Materials (CNM) Nanophotonics Group have carried out experiments that shed new light on how this process occurs. Using polarization selective ultrafast spectroscopy on RC single crystals, the team was able to resolve cofactor-specific photochemistry and identify the nanometer-scale delocalized character of the first light-generated excited states.

This work is significant because overlapping spectral features of the cofactors have up to now precluded clear resolution of the spectral and temporal response of the individual cofactors to photon absorption, and limited our understanding of the complex photochemical function in RCs. Using the CNM's ultrafast transient absorption spectrometers, individual cofactors in RCs were monitored through careful orientation of the polarizations of the pump and probe pulses relative to the crystallographic axes of the single crystals.

The impact of this work is that it provides a clearer, more detailed picture of the first steps in photosynthetic energy conversion, identifies a role for delocalized excited-states, and provides new experimental and data analysis approaches for studying the unusual efficiency of light harvesting and processes in natural photosystems.

Explore further: A nanosized hydrogen generator

More information: L. Huang et al., Proc. Nat. Acad. Sci., 109 (13), 4851 (2012).

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kevinrtrs
1 / 5 (7) Apr 18, 2012
Across billions of years of evolution, Nature has retained a common light-absorbing hexameric cofactor core for carrying out the very first chemical reaction of photosynthesis, the light-induced electron transfer across approximately 3 nm.

Note that this evolutionary dogma contributes nothing to the research. One can quite happily erase it and it wouldn't make any difference to the outcome or the subsequent application.

This is the single most important concept that evolutionaries need to understand but actually refuse to accept: The rest of the research is done in the present and various other people can perform the same experiments and obtain similar results[or NOT].

The same cannot be said about the evolutionary pseudoscience because no one can go back into the past and verify that it was so. Even digging up and examining fossils does not help with that. It just cannot be done.
As for the results themselves: There's no way it could have "evolved". It's irreducibly complex
Mike_Massen
2.3 / 5 (6) Apr 18, 2012
kevinrtrs cant read my posts or process issues of probability & paradigm of "permutation space" & made more facile claims:-
As for the results themselves: There's no way it could have "evolved". It's irreducibly complex
Please define "irreducibly complex" in very direct and simple means and no PleasE dont link to propaganda sites replete with ads & vague notions of creationism never approached experimentally.

Evolution is observable in the laboratory in respect of many simple life-forms and has been observed in nature over longer periods with rather more complex life-forms, do you deny all these observations of thousands of people in routine university education ?

Never heard of acquired anti-biotic resistance, seriously ?

Are you arbitrarily claiming evolution with more complex life-forms & structures (you cant understand) is impossible & "no way" you can conceive/imagine occurrences ?

Then if so, therefore you must be confirming you are completely impotent in that respect.