Page 36 - The Miracle of Protein
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34      THE MIRACLE OF PROTEIN



                        ting the chains comprising the protein to bind tightly together,
                        which increases the tensile strength of the collagen fibers. Col-
                        lagen fibers are known to have greater tensile strength than
                        steel. If a longer side-chain amino acid were used in place of
                        glycine, the resulting collagen fibers would not possess the same
                        level of tensile strength. At the same time, were it not for

                        glycine, the collagen fibers would also lack enough strength to
                        bind cells to one another.
                            As you can see from this brief description, there is con-
                        sciousness and planning behind the selection of these 20 specif-
                        ic amino acids from among the 200 available. Had this selection
                        taken place at random, then the proteins necessary for life could
                        never have formed. If only a single amino acid were any differ-
                        ent from how it needs to be, a vital function would collapse, and

                        life would become impossible.
                            As we have seen, conscious systems, rational selection, and
                        order exists in every phase of life.




                            PRIMARY AND SECONDARY PROTEIN STRUCTURES


                                                                - R-groups are found in the
                                                                outer part of the helix.
                                                                - Hydrogen bonds stabilize
                                                                the helix.
                                                                - Proline, apolar and polar
                                                                groups destabilize the helix.





                                                                left: amino acid chain with
                                                                ‘alpha-helix’ side chain
                                                                right: amino acid chain with
                                                                ‘beta-sheet’ side chain
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