Page 173 - The Miracle in the Cell Membrane

Harun Yahya (Adnan Oktar)

uses only a very small part of this sugar, and the remain der
is trans ferred to the brain. Yet the struc ture of the trans port
mol e cu les is still a mys tery to sci en tists. In all like li hood,
the trans port ers are one or more pro teins that open the
chan nels so as to per mit glu cose to pass through the cell
mem brane.
Amino acid trans port sys tems are far more com plex,
because every one of the 20 amino acids has a dif fer ent
molec u lar struc ture. These can be grouped into four class -
es depend ing on their chem i cal prop er ties: large neu tral,
small neu tral, basic and acid ic. Each cat e go ry has its own
trans port sys tem. As with glu cose trans port ers, large neu -
tral amino acid trans port ers lie on both sides of the bar ri er,
and amino acids can thus enter and leave the brain. Small
neu tral amino acids can be syn the sized by the brain cells,
so there is no need for them to be trans port ed to the brain.
The idea of the blood-brain bar ri er was first advanced
by the German bac te ri ol o gist Paul Ehrlich at the end of the
19th cen tu ry. It was pos si ble to be proved, how e ver, only
with the devel op ment of the elec tron micro scope in the
1950s. Although in appear ance cap il la ries in the brain
resem ble the veins in other parts of the body, they pos sess
dif fer ent fea tures. First of all, the con nec tions between cells
in the cap il la ry vein in the brain are exceed ing ly dense. At
their con nec tion points, cell mem branes are attached to one
anoth er just like a zip per. Unions between the endo the li um
cells in the cap il la ry ves sels in the other parts of the body
have spa ces. Second, in cells in the brain's cap il la ry ves sels,
there are very few pin o cy to sis sacs that help trans port flu -

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