Answer 1:
Well, sort-of. I'm curious to know where you
have heard this! First off, biological
membranes are made of phospholipids - that is,
triglyceride molecules that have two fatty acid
chains attached to them and onephosphate ion. For
reasons having to do with weak chemical
interactions called Van der Wall's forces, these
molecules tend to form bubbles and other membranes
when placed in water. Now, proteins placed inside
of these things have been observed to exhibit
metabolism, making more of the protein and more of
the phospholipids by turning other things in the
environment into more of themselves. These "other
things" in this case includes other
already-produced proteins; proteins that can turn
other proteins into themselves are called prions,
and what they do is they take an existing protein
and change its shape without changing its chemical
formula. Obviously, this means that the prion
needs to have the protein available and be of the
same chemical composition itself, since it cannot
create atoms. But in any case, these
protien-phospholipid complexes, called
coacervates, can, if they have the right stuff in
them, get larger, and eventually break up into
more of themselves. This division is uncontrolled,
however, and they can only"live" off of material
that has already been made for them by living
cells, rather like viruses. So far, nobody
has managed to create anything that is able to
regulate its own metabolism or take molecules
formed by nonliving processes and turn them into
more of itself. That, it seems to me, is something
of a prerequisite for creating life - while we can
argue that viruses and prions are alive, perhaps,
they are alive only through the presence of living
cells, and cannot exhibit life without them. The
question of how life started is how cells got
started. That said, coacervates DO provide an
interesting possibility of how REAL life might
have gotten started. Click Here to return to the search form.
|