Among the many intricate cellular processes on planet earth, photosynthesis stands apart. Unlike other cellular processes, photosynthesis is not just necessary to keep the plant or other photosynthetic organism alive, it is necessary for there to be any form of aerobic life. This article will discuss the photosynthetic process in a broad, general sense, and show how it relates to the origins debate.
Photosynthesis is an extremely complex, multi-step process that takes the energy from the sun and uses it to create energy usable by the photosynthetic organism, most usually plants. Any five year old knows that they need to eat to survive, they do not just magically get food from the sun. While plants cannot metabolize the suns energy directly, the process of photosynthesis allows them to take that energy and turn it into something they can use. The end product of photosynthesis is the plants food, a sugar called glucose.
In order to form glucose, the plant must undergo photosynthesis. The process begins mostly in the leaves, though some stems perform it as well. Plant leaves are largely green. This is due to a high concentration of the pigment chlorophyll, contained in structures called chloroplasts. This chlorophyll pigment serves a dual purpose. The pigment provides color to the leaf by reflecting green light, but it also absorbs all other wavelengths of light. This generates the energy necessary to perform photosynthesis. A single packet of light is called a photon. When one of these is absorbed by a chlorophyll molecule, it causes the molecule to release an electron. The chlorophyll molecule replaces its missing electron by stealing one from a nearby water molecule. This splits the water molecule. The original electron is taken into something called the electron transport system, which is a pathway of polypeptide proteins. A special molecule called NADP, acts as a transport for the electron between proteins. As the electron passes through the proteins, it gradually loses energy. This lost energy is used to create ATP from ADP. ATP is cellular energy. The abbreviation stands for Adenosine tri-phosphate. In its un-energized state, it is known as ADP, Adenosine di-phosphate. When an ATP molecule is used for energy, it loses one of its phosphates, reverting to ADP. Some of the ATP produced here will be used up in the next step, known as the Calvin Cycle.
The plant uses the Calvin Cycle to produce its food The light-dependent reaction listed above is merely fuel for the Calvin Cycle. Without the light dependent reaction, the Calvin Cycle would lack the necessary energy to function. As part of the Calvin Cycle, Carbon Dioxide, which the leaf had previously pulled out of the atmosphere using special enzymes, is used to form sugars that the plant can use for food. In order to do this, the plant uses some of the NADPH generated in the previous light-dependent reactions to split carbons off from the carbon dioxide molecules. This produces oxygen gas as a byproduct, which will be released into the atmosphere. The Carbon molecules bind with each other and spare hydrogens from the NADPH to form three carbon chains. The NADPH, upon losing its hydrogen, becomes NADP+. The three carbon chains are then combined to form polypeptides, such as glucose, sucrose and starch all of which plants can use for food. However, sucrose and starch are generally formed when the plant has enough food for its needs and is storing food for future use, whereas glucose is used for more immediate plant needs. The equation for the whole photosynthetic reaction is below. The equation leaves out the need for chlorophyll in the process, but, as chlorophyll is neither created, nor consumed in the process, this is understandable. Note that the process produces glucose, and six gaseous oxygen molecules as a net result.
The above is a very basic description of the photosynthetic process. Whole college courses could be devoted to the minutia of photosynthesis. For anyone who wants more details, I have linked to a very detailed article at the bottom of this page. However, even the basic description above shows how deep photosynthesis is. The number of specialized chemicals and processes involved for the plant or other photosynthetic organism is breathe taking. Evolutionists must be able to explain how this complex process originated. Their explanation is that it evolved in bacteria around four billion years ago. They further claim that, since there was supposedly no oxygen on earth until around 3.4 billion years ago, that the bacteria which first underwent photosynthesis did so without oxygen, using sulfur and hydrogen. When oxygen finally did evolve, these creatures supposedly somehow evolved to be able to use it until about 2 billion years ago, when oxygen supposedly became prevalent.
The evolutionary explanation for photosynthesis does not explain how photosynthesis developed, nor does it make logical sensed based on current observation. There is no reason why anaerobic bacteria, which largely feed using a fermentation reaction, would need to develop photosynthesis, nor is there a pathway to do so. Fermentation breaks down sugar, photosynthesis makes it. Further, both fermentation and photosynthesis require the existence of elemental oxygen. Sugars contain oxygen molecules and are present in both reactions. Photosynthesis requires water and carbon dioxide, both of which also require elemental oxygen. Photosynthesis thus had to have evolved at the same time or after elemental oxygen. There is no evidence for bacteria photosynthesizing using any other element. Even if they had done so, they could not have produced sugar, which is the key resultant product of photosynthesis in terms of nutrients for the organism. The whole photosynthetic reaction would have to have been redesigned multiple times for the evolutionary theory to work, something for which there is no evidence.
While evolutionists continue to insist in oxygen-less photosynthesis, creationists can look at the process and marvel at the complexity built into the world around us. Who but a loving God would design plants to use the waste product of animal breathing, (carbon dioxide) and design animals to use the waste product of photosynthesis(oxygen)? The sheer impossibility of that being coincidental points to an all powerful Designer Who created the earth to function in harmony, just as it does today.