Friday, December 4, 2015

More Protein Wonders

Proteins begin their lives as chains of amino acids in the body. In humans, protein-forming amino acids are either acquired in foods we eat (essential amino acids) or are manufactured in our body (non-essential amino acids). Essential and non-essential amino acids are coded by the DNA molecule to produce the proteins of the body. Twenty different protein-forming amino acids are chained together in myriad  ways according to instructions in the oft-cited DNA code. The human body operates with many thousands of different proteins.

The term DNA code is a powerfully meaning-laden term. When we were young some of our entertainments were games of code-cracking or secret code-breaking. In every case the code was devised by another person, an indicator of intelligence of the deviser of the code. They also affirm our own ability as intelligent code breakers. In the DNA code we observe that when we recognize the identity of the code author, our own sense of perception and comprehension is affirmed.

Are there limits to the number of proteins possible? Bioscientists speculate that there are as many as ten million different proteins among all living things on earth, while humans have upwards of 50,000. Proteins begin as chains of amino acids termed polymers. We highlight a fascinating capability of proteins: their ability to fold into three dimensional shapes. The three dimensional shape relates to the function of that particular protein in keeping with the biological principle of “form fits function.” In theory, there are no limits to the number of possible proteins. 

The unique three dimensional conformation of each protein, according to scientists, is dictated by the original amino acid sequence. Scientists also attribute the three dimensional structure to the mediation of other protein cells, assisted by molecular “chaperones.” These explanations point to a possible cause, but not an entirely satisfying explanation of how the cause works to accomplish the observed effect. Herein is a mystery. The line between a naturalistic cause and effect, such as the forces we exert to accomplish minor repairs of an inoperative device in our home, and a complex phenomenon such as protein folding, is not always sharply defined.

In early science lessons we learned that “proteins are the body’s building blocks,” rather like bricks and lumber incorporated into a new home. The three-dimensional conformation of complex protein molecules may help us envision the idea of “building blocks.” While this characterization of proteins is accurate, the story is incomplete. Three-dimensional protein molecules have many functions in the human body. The functions include enzyme catalysis of metabolic reactions, immune responses, cell signaling, and information processing. Each previous term could be the subject of lifetime study by specialists in bioscience. 

Where does a divine miracle end and a natural process begin as we study the astounding complexity of life—in particular, human life? We may easily perceive physical life forms and life processes as intelligently designed. We may also go further to say that human life forms are the product of a divine, transcendent miracle. As we contemplate the existing complexity of physical body structure and the functions operating to make its systems work, we are struck with wonder. God is the author of both primary causes and secondary causes. Primary causes are transcendent miracles of creation such as the beginning of our universe and the immediate creation of human life forms. Secondary causes are moment to moment transformational or sustaining miracles such as the miracles of our working bodies.