Thursday, August 30, 2012

Crucially important Chlorophyll f

Stromatolites today
Hamelin Pool Marine Nature Reserve, Australia
Lecture materials in Florida International University FIU

"Chlorophyll f was announced to be present in cyanobacteria and other oxygenic microorganisms that form stromatolites in 2010." (wikipedia)
The point is that chlorophyll f is able to use infra-red light for energy.

Quite a point!

Chemical structure
The only chemical difference between chlorophyll f and a is an additional oxygen atom and two less hydrogen atoms in f.

Chlorophyll f        Chlorophyll a
C55H70O6N4Mg    C55H72O5N4Mg

How can such a small structural difference make such a big functional difference?

Origins of atmosphere!

Cyanobacteria cell

The presence of chlorophyll f in cyanobacteria is of utmost theological significance for Creation.

The earliest currently known signs of life on planet Earth are cyanobacteria found on about 3.5 billion years old basalt in West Australia [myBlog].

Scientists suggest that cyanobacteria began to produce oxygen using photosynthesis and that eventually Earth got the atmosphere from this process. Oxygen rich atmosphere and water make life possible as we know it. Chlorophyll f would be the engine for that - and with infra-red!

Theological significance
If it turns out that this is what actually happened at the beginning of life upon Earth the process is  highly significant when we look at the grander picture of life on our planet. There was no haphazard random beginning of some anomalous organic thing that evolved into this and that. Instead, the beginning of life on Earth in oxygen producing highly sophisticated bacteria with DNA seems ludicrously important and meaningful for the entire Creation.

Don't you agree?

Wednesday, August 29, 2012

Chlorophyll molecule photosystems

Wikipedia encylopedia tells
Chlorophyll molecules are specifically arranged in and around photosystems that are embedded in the thylakoid membranes of chloroplasts.

In these complexes, chlorophyll serves two primary functions. The function of the vast majority of chlorophyll (up to several hundred molecules per photosystem) is to absorb light and transfer that light energy by resonance energy transfer to a specific chlorophyll pair in the reaction center of the photosystems.

The two currently accepted photosystem units are Photosystem II and Photosystem I, which have their own distinct reaction center chlorophylls, named P680 and P700, respectively. These pigments are named after the wavelength (in nanometers) of their red-peak absorption maximum.

The identity, function and spectral properties of the types of chlorophyll in each photosystem are distinct and determined by each other and the protein structure surrounding them. Once extracted from the protein into a solvent (such as acetone or methanol), these chlorophyll pigments can be separated in a simple paper chromatography experiment and, based on the number of polar groups between chlorophyll a and chlorophyll b, will chemically separate out on the paper.

How does this wonder of nature work?

Discovery of chlorophyll structure

Chlorophyll is among the finest masterpieces of God's creation of natural world and is not exactly a simple thing. It has taken some of the sharpest minds of humanity to try to decipher what it is that makes plants green and how it works in its vital tasks in making life possible on planet Earth. The work of leading scholars has been rewarded with several Nobel prices in recognition of its significance. Chlorophyll research is still going on with full steam today as a hot topic of molecular biology.

Richard Willstätter
Richard Willstätter (1872-1942)
Scientists first began to recognize the molecular structure of chlorophyll at the beginning of the 20th century especially through the work of the German organic chemist Richard Willstätter (1872-1942).

Of Jewish origins from Karlsruhe, Richard Willstätter worked from 1896 in the University of Munich. In 1905 he moved to  ETH Zürich where he solved the structure of chlorophyll a and b.

Willstätter received the 1915 Nobel Price in Chemistry for studies on the structure of plant pigments and especially chlorophyll. (Presentation of the price)

ETH Zürich ranks among the top universities in the world and its researchers have so far received 20 Nobel prices, most recently in 2010.

Willstätter's discovery was the first time that the element Magnesium (atomic weight 12) was found to have a central role in the functioning of living organisms.

Hans Fischer
Hans Fischer (1881-1945)
In 1940 the structure of chlorophyll was described in fuller detail by another German organic chemist Hans Fischer (1881-1945). He won the 1930 Nobel Price in Chemistry for his work on the pigments in blood (bilirubin, haemin), bile, chlorophyll in plant leaves, and the chemistry of the fundamental element in all of them, pyrrole.

Just at the end of Second World War his Munich institute and his life work there were destroyed in Allied bombing. This was too much for Hans Fischer and he committed suicide March 31, 1945. (Germany surrendered unconditionally May 2, 1945).

Robert Burns Woodward
Robert Burns Woodward (1917-1979)
In 1960 American chemist Robert Burns Woodward (1917-1979) published a total synthesis of the chlorophyll a molecule using as research tools both infrared and nuclear magnetic resonance spectroscopy and stereochemistry.

R.B. Woodward is considered among the finest organic chemists of the 20th century. In 1965 he received the Nobel Price in Chemistry for his outstanding work on organic synthesis (ref).

Following Woodward's example, "synthetic chemists have always looked for elegance as well as utility in synthesis" (ref). In doing this they are emulating the Creator of the world who combines functionality and elegance in all His works!

Ian Fleming
Ian Fleming (1935-) Home page
In 1967 an updated full model of chlorophyll a molecule was presented by English organic chemist, University of Cambridgen professor Ian Fleming (1935-) .

Molecular structure of chlorophyll a

3-D model of chlorophyll a molecule
The chemical formula of Chlorophyll a is C55H72O5N4Mg

The heart of chlorophyll a - which is the most common form in Nature - has a single Magnesium ion (green in the model). The core is surrounded by four Natrium (blue) and five Oxygen atoms (red) and framed in 55 Carbon (black) and 77 Hydrogen atoms (white).

The long "antenna" is a phytol chain. "Phytol is an acyclic diterpene alcohol that can be used as a precursor for the manufacture of synthetic forms of vitamin E and vitamin K1. In ruminants, the gut fermentation of ingested plant materials liberates phytol, a constituent of chlorophyll, which is then converted to phytanic acid and stored in fats." (wikipedia)

Chlorophyll a structure

Tuesday, August 28, 2012

Why green leafs instead of black ?

Green chlorophyll and sunlight
Green nature wallpapers

The somewhat surprising question in the title comes from the fact that Nature could utilize sunlight more efficiently if chlorophyll would be black. By rejecting the green wavelength plants get their green colours but loose part of the energy arriving from the Sun .

Word chlorophyll is derived from Greek words χλωρος, chloros ("green") and φύλλον, phyllon ("leaf").

Chlorophyll is crucially important for life on planet Earth as it is in the core of photosynthesis. It is a very complicated molecular structure built on Magnesium atom with its antennae for catching photons. Chlorophyll is used by green plants and also by some important bacteria and algae.

Klorofylli A ja B torjuvat vihreän valon taajuuden
Why green?
According to modern understanding all natural chlorophyll has its origins in the earliest life forms when algae were producing it. But why they reject green light?

Evolutionary Biology is unable to explain why since for the survival of the fittest it would seem more efficient to utilize the entire spectrum leaving chlorophyll black. Shil DasSarma from the University of Maryland suggest that we should not view evolution as a strictly optimized engineering project. As in the case of chlorophyll being green, evolution is not natural engineering that automatically chooses the best fit. Rather, evolving life has to deal with the realities of the environment and accidents of life and is organic rather than mechanical. According to Berman life forms evolve according to the conditions, limitations and possibilities given by reality and not by pure utilitarian logic and natural laws aimed at fitness peak.

Early life on Earth may have been a theatre for bitter fight for survival of the fittest in competition for energy with possibly dominating single cell arkhea that used especially green light through retinal (vitamin A aldehyde) molecule. Perhaps competition from such pink life forms pressured algae to evolve towards chlorophyll processes that reject green light. (Why would energy form a given color in the spectre of sun light be exclusive, though?)
(Read more about DasSarma's views in LiveScience 2007).

Scientific research progresses in this way by questioning also apparently self-evident facts and by suggesting new and challenging theories and hypotheses.  In the evolution of Evolutionary Biology some ideas survive, grow and develop while others wither and die and are thrown in the dust bin of the history of science.

Theological comment
And God said, “Let the water under the sky be gathered to one place, and let dry ground appear.” And it was so. God called the dry ground “land,” and the gathered waters he called “seas.” And God saw that it was good.

Then God said, “Let the land produce vegetation: seed-bearing plants and trees on the land that bear fruit with seed in it, according to their various kinds. ” And it was so. The land produced vegetation: plants bearing seed according to their kinds and trees bearing fruit with seed in it according to their kinds. And God saw that it was good. And there was evening, and there was morning —the third day.
Genesis 1:9-13 NIV
It would be rather sad if the leafs of the plants were black and grey, wouldn't it?

So let us praise the Lord for the green colour of chlorophyll that together with the majestic Sun create not only oxygen and sugar for all living creatures but also make the Nature so beautiful in the eyes of us people created in His image!