To fully gain an insight into these interactions' complexity, we must conduct an in-depth study and observation of the processes taking place. Initially, the sun's released energy must be made useful to our body's cells, for direct sunlight on its own is not useful. Energy from the sun, along with water from the soil and carbon dioxide released from all living organisms, synthesizes oxygen and sugars (including glucose) within the leaves of green plants. This seemingly simple but very complex process is called photosynthesis. Without the oxygen and glucose required to generate usable energy (in the form of ATP* molecules), no human or plant cells could survive, although some exceptions are known.(2) Hence, all photosynthetic organisms on Earth an indispensable sources of oxygen for all life-forms.
The two main sources of oxygen are rain forests and oceans, where green algae and photosynthetic bacteria live.(3) In fact, algae lying 120 meters beneath the Antarctic ice is fully equipped to serve life. These algae have been found in sponges with a system of fiber optics that allows them to gather the minute amount of light reaches the Antarctic Ocean's murky depths and direct it to photosynthetic algae.(4) Given this, we must say that photosynthetic life-forms are in complete submission to and serve other life-forms, among them humanity.
Plant and tree leaves are optimally designed, both physically and biochemically, to generate vital oxygen and sugars. A leaf's large surface area is required for the optimal interception of solar energy, while the thin cross-section is essential for the fast transport of oxygen and carbon dioxide in and out of the leaf.
Specific photosynthetic cells are arranged in between the leaf's two protective epidermal layers. Carbon dioxide and oxygen molecules, under specific guidance, leave the leaf through specific pores flanked by cellular gates or guard cells situated underneath each leaf, as the leaf's upper layer is covered with a protective waxy layer. This waxy layer is essential, for without it the leaf would dry up. For example, on hot days 100 gallons of water are lost from cottonwood trees.(5)
All evaporated water is collected as clouds (water vapor near the condensation point), from which pure, condensed water falls as rain. Likewise, all animals' breath contains water vapor (released during the breakdown of glucose for energy release), which is also created as clouds and recruited as a moving source of potential water for all needy plants and living organisms.
Water's continual recycling between the land and oceans to the clouds prevents wastage and provides a continually renewed source of fresh water to synthesize oxygen during photosynthesis. It also serves as a medium in which all biochemical reactions must take place in living cells.
Moreover, a leaf has no knowledge or power to generate oxygen and sugars, which are vital for all living cells, for it has never seen or experienced any direct contact. For carbon synthesis to occur, oxygen atoms must be torn from water and carbon dioxide molecules. This requires knowledge and power, since neither solar energy nor a leaf possess these. Also sugars, an indispensable food source for all life-forms, cannot be synthesized by coincidence in a weak and powerless leaf.
This complementary relationship indicates that all these simultaneous interconnections could only take place according to a program dictated through an all-pervading knowledge, willpower, and mercy. Likewise, only One with such attributes could subject, direct, and allowing these processes to continue.
Moving at extremely high speeds (around 346m per second),(6) oxygen molecules released from such photosynthetic life-forms as plant and tree leaves, and bacteria and algae in the oceans, must reach the lungs of all living organisms. They also must be dissolved in water so that fish and other marine organisms can breathe. In fact, all of these processes must take place continuously so that each organism can live until its appointed time. This means that the oxygen molecules must be guided through the atmosphere and into each living organism so that each molecule's optimal and perfect function may be carried out. Thus, although moving at extremely high speeds, each molecule's function remains in the best and optimal manner.
Each lung is a highly delicate organ composed of millions of microscopic tunnels ending in tiny sacs (alveoli) encapsulated with a dense capillary (thin artery) network.(7) Oxygen molecules in the atmosphere are inhaled and brought to the sacs, which send oxygen (from within the sac) into the bloodstream, and carbon dioxide is diffused from the bloodstream into the sacs. Although the air we breathe contains a large proportion of nitrogen, it is mainly oxygen that is pulled through the sac's wall, across the thin arterioles' microscopic walls, and into the bloodstream's red blood cells. Each oxygen molecule is then complexed and surrounded by a huge molecule of hemoglobin (the oxygen-carrying protein in red blood cells). Although these processes take place very quickly, every step occurs with exceptional precision and accuracy.
To reach the trillions of functionally different cells, the red blood cells must be pumped there with a great force. Therefore, all oxygenated red blood cells coming from the lungs are directed immediately to the heart. This masterpiece works continuously from birth until death, pumping fresh blood from the lungs to the tissues, and simultaneously pumps oxygen-deprived blood from the tissues to the lungs.(8)
Red blood cells flow through the arteries with great force. When they reach the thinnest arteries (capillaries) at tissues that are only one-cell thick, they almost align in a single queue within the capillaries and move carefully until the oxygen they carry is diffused to the surrounding needy tissue cells. At the same time, the waste gas of carbon dioxide is diffused quickly from the tissue cells into the blood plasma. The red blood cells then are directed into the veins, loaded with waste gas, and sent back to the heart (this requires great energy, as the blood returns to the heart at a very low pressure). From here, the oxygen-deprived red blood cells are pumped back to the lungs to be oxygenated. In the lungs, carbon dioxide is directed out to the sacs and exhaled into the atmosphere.
As creation contains no waste and every existence is useful, this waste gas is recaptured during photosynthesis to create vital oxygen, thereby displaying an unprecedented example of complementarity. Thus solar energy is harnessed to generate oxygen and provides a means of generating energy beneficial to cells (chemical energy). The oxygen created in this process is taken through multiple steps and stages until it is made available to the cells.
Here, we see a clear manifestation of perfect bounty and grace, for the cells needs are brought to them from afar and with extreme care after going through multiple ordered steps that easily could be disturbed. One insight we acquire is that each step takes place rapidly yet accurately, and so must require an infinite power and knowledge to occur.
We, Earth's most intelligent creatures must admit our relative inability and impotence to understand fully or even to control any of these perfect processes. Rather than behave according to our vested interests and suppose Earth to be under our control, we should seek to understand our responsibility to know that all of these processes are somehow connected with us and subjected for our benefit in so many ways that conscious gratitude and faithfulness are required.
2 Richard Monastersky, Deep Dwellers: Microbes Thrive far below Ground, Science News 151 (29 Mar. 1997):192-93.