Page 110 - The Cell in 40 Topics

The Cell in 40 Topics

Figures 87 and 88.
After receiving instructions as to where to go in the
cell—and how—newly synthesized proteins go where
they are programmed. There exists a
perfect order in
this world, too
small to be
seen with
the naked
eye.

Let us now exam-
ine the protein’s journey in-
side the cell in greater detail
(Figures 87 and 88).
When we look at how
every new-synthesized protein is to pass to the endoplasmic reticulum re-
gion, for instance, we see the following: Firstly the code is “read” by a mol-
ecular component known as SRP—another protein with the best possible
design for deciphering the code and helping the protein find a channel
through which to pass. It solves the special information in the protein and
then combines with it, acting just like a guide. Together, the SRP compo-
nent and protein later attach to a special receptor that is waiting for them in
the endoplasmic reticulum membrane, and the protein attaches to the entry
channel. With the receptor being stimulated in this way, the channel in the
membrane opens—at which point, the SRP separates from the receptor.
All these processes take place with flawless timing and in perfect har-
mony. But at this stage, the protein faces another problem. As we know, pro-

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