GAIA INCREDIBLY CREATIVE e.g. in PHOTOSYNTHESIS

 THE MIRACLE OF PHOTOSYNTHESIS

TOO HOT OR TOO COLD ...

Our Earth was formed about 4.4 billion years ago as one of the planets orbiting our sun. It is the only planet that supports biological life. The planets closer to the sun (Mercury and Venus) are too hot, and the other planets, which are further away from the sun, are too cold for biological life: Mars, Jupiter, Saturn, Uranus, and Neptune.
Our Earth, amazingly, has just the right balance: the heat from the sun, the heat from the glowing core of the Earth itself, liquid water, and the mantle of the atmosphere. And so, by earthly standards, a very thin shell (around 20 km thickness) has formed, in which all life, plants and animals, from microscopic creatures (such as bacteria and fungi) to large plants and animals, can thrive.

A WONDERFUL SYNTHESIS

About 4 billion years ago, the first forms of life began to emerge. It started out extremely small, with cells in the depths of the oceans that did not even have a nucleus.
But soon (i.e., after about 100,000 years), a process began that provided food for growth, a process called photosynthesis: “photo” stands for light, which undergoes a synthesis with water and (the gas) carbon dioxide. A wonderful trio. And of course, that didn't happen just like that.
In a long process, very special molecules had been created, the most important of which was chlorophyll. This is a molecule that is activated by light, which resonates with sunlight, just as a tuning fork resonates with certain frequencies in music.

By absorbing the energy of light, the chlorophyll molecule is able to split water into oxygen, charged hydrogen atoms, and electrons.
The oxygen is released into the atmosphere and the other products of the splitting of water ingeniously interact with carbon dioxide gas and ultimately form a ring-shaped molecule that we call glucose, one of the forms of sugar.

It is easy to say, “they ingeniously work together.” In fact, it is an unimaginable achievement of nature to form the complex molecules that ultimately produce the relatively simple molecule glucose (see image: black=carbon, red=oxygen, gray=hydrogen).

AN UNIMAGINABLE ACHIEVEMENT

Despite extensive research, we still do not have a complete picture of how this formation began and continued.
It is now clear that the origin lies with primitive organisms at the bottom of the oceans, but the exact steps are still difficult to visualize. Nature appears to be incredibly creative. It works empirically, countless times through trial and error, always a little different, always something new, until it ‘fits’ and ‘works’... and then it continues to build... We cannot understand how the most beautiful and extremely complex molecules came into being in this way - and then after that also the ‘interplay’ of so many different molecules.

After the creation of the earth, it began with the interaction with the sun, which radiated a large amount of energy and caused the earth to change more and more. It differentiated further and further, more and more new ‘things’ were created, and as a result, everything became more complex and complicated. It must have taken countless attempts and steps before such a complex molecule as chlorophyll was created. And then, after it was ‘activated’ by the power of sunlight, how it ultimately produced glucose in collaboration with other molecules. And that glucose is in turn the beginning of the food that is necessary for the growth of plants. Many animals live off plants—or off other animals, which ultimately also live off plants.

GREEN NATURE

Chlorophyll is the molecule that makes all of nature green. Painters will tell you that green is the most ‘natural’ color—and we know that too. Green is the color of health, growth, and life. All green plants are engaged in the process of photosynthesis: producing the raw material for all further nutrition for themselves (their own growth). AND, not to forget, they also produce oxygen, without which we cannot live.
We breathe in oxygen and breathe out carbon dioxide—and that is how we stay alive. Conversely, plants use that (exhaled) carbon dioxide to give us oxygen again. It is a very special, indeed vital, cycle that revolves around the process of photosynthesis.
We can feel a sense of admiration and gratitude when we see all that greenery that surrounds us in abundance and is so indispensable to our lives!

This is the main thing I would like to share about this wonderful process, which has been going on for billions of years. The admiration of this NATURAL WISDOM.


WANT TO KNOW A BIT MORE?

For those who want to go a step deeper, here is some additional information. Perhaps it will increase your admiration?

The BASIC REACTION of photosynthesis is:

    6 CO2 + 6 H2O + light energy > C6H12O6 + 6 O2   (C6H12O6 = glucose)

This process can be divided into two main phases:

1. Light-dependent reactions:
These take place in special membranes of the chloroplasts in the cell, the organs that contain chlorophyll.
     a - Chlorophyll absorbs sunlight, which provides the energy to split water molecules, i.e., the photolysis of water, which is split into oxygen (O2), protons (H+), and electrons.
       b - The energy from the light acts on the substances ATP and NADPH. These are energy-carrying molecules that are used in the next phase.
       c - Oxygen (O2) is released into the atmosphere as a by-product.

2. Light-independent reactions:
    These take place in the supporting tissue (stroma) of the chloroplasts.
       a - Carbon dioxide (CO2) is fixed by the enzyme Rubisco and converted into an organic compound that ultimately forms glucose.
       b - During this process, ATP is used as an energy source and NADPH as a reducing agent to convert step by step CO2 into glucose (C6H12O6).

Photosynthesis is extremely important because it supplies oxygen to the atmosphere, which is essential for life on Earth. The glucose produced is essentially a form of chemical energy that plants use for growth and maintenance. Other organisms, such as animals (including us, humans), obtain this energy by eating plants (and the eaters of plants).

In sum: it starts, as said, with the ‘capture’ of light energy by chlorophyll in the chloroplasts. That energy is used to split water and release oxygen, while ATP and NADPH are formed. In the next phase, carbon dioxide is converted into glucose using the energy from ATP and the action of NADPH.

ATP (adenosine triphosphate): provides energy for many processes in living cells (here for photosynthesis, but also, for example, for muscle contraction).
NADPH (nicotinamide adenine dinucleotide phosphate): This is an essential electron donor for reduction processes.

BLUE - RED - GREEN ...
It is interesting to note that chlorophyll does not use the green part of the sunlight spectrum, but higher and lower frequencies than those of green, i.e. more blue (higher energetic) and red (lower energetic). Green is reflected back - and that is why everything is basically green! The absorption spectrum (see graph) for two types of chlorophyll clearly shows this.


Johan Muijtjens
2-11-2024