The Biology of Belief - Bruce H. Lipton [23]
Figure A shows the preferred conformation of our hypothetical protein backbone The repelling forces between the two negatively charged terminal amino acids (arrows) causes the backbone to extend so that the negative amino acids are as far apart as possible Figure B shows a close-up of an end amino acid A signal, in this case a molecule with a very positive electric charge (white sphere), is attracted to and binds with the negative site on the protein’s terminal amino acid In our particular scenario, the signal is more positive in charge than the amino acid is negative in charge After the signal couples with the protein, there is now an excess positive charge at this end of the backbone Since positive and negative charges attract one another, the backbone’s amino acids will rotate around their bonds so that positive and negative terminals will come closer together Figure C shows the protein changing from conformation A to conformation B Changing conformations generates movement and the movement is harnessed to do work, providing for such functions as digestion, respiration, and muscle contraction When the signal detaches, the protein returns to its preferred extended conformation This is how signal-generated protein movements provide for life
The shape-shifting proteins exemplify an even more impressive engineering feat because their precise, three-dimensional shapes also give them the ability to link up with other proteins. When a protein encounters a molecule that is a physical and energetic complement, the two bind together like human-made products with interlocking gears, say an eggbeater or an old-fashioned watch.
Examine the following two illustrations. The first shows five uniquely shaped proteins, examples of the molecular “gears” found in cells. These organic “gears” have softer edges than machine shop-manufactured gears, but you can see that their precise, three-dimensional shapes would enable them to securely engage with other complementary proteins.
Protein Menagerie. Illustrated above are five different examples of protein molecules. Each protein possesses a precise three-dimensional conformation that is the same for each copy of itself in every cell. A) Enzyme that digests hydrogen atoms; B) Woven filament of collagen protein; C) Channel, a membrane-bound protein with hollow central pore; D) Protein subunit of “capsule” that encloses a virus; E) DNA-synthesizing enzyme with attached helical DNA molecule
In the second illustration (p. 29), I chose a wind-up watch to represent the workings of the cell. The first picture shows a metal machine, revealing the gears, springs, jewels, and case of the watch model. When Gear A turns it causes Gear B to turn. When B moves it causes Gear C to turn, etc. In the next image, I overlay the human-made machine gears with softer-edged organic proteins (magnified millions of times in proportion to the watch) so that it becomes visually conceivable that proteins could be like the watch’s mechanism. In this metal-protein “machine,” one can imagine Protein A rotating and causing Protein B to revolve, which in turn causes Protein C to move. Once you see that possibility, you can look to the third figure in which the human-made parts are removed. Voilà! We are left with a protein “machine,” one of the thousands of similar protein assemblies that collectively comprise the cell!
Cytoplasmic proteins that cooperate in creating specific physiologic functions are grouped into specific assemblies known as pathways. These assemblies are identified by functions such as respiration pathways, digestion pathways, muscle contraction pathways, and the infamous, energy-generating Krebs cycle, the bane of