Page 36 - The Miracle of Protein

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