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| Science Forum Index » Bio Evolution Forum » Text Support for C/A Evolve Separately... |
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| Tom Hendricks... |
 Posted: Wed Oct 21, 2009 6:47 am |
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Catabolic and Anabolic pathways must be separate.
Catabolic and Anabolic are regulated by enzymes.
Enzymes have evolved to specialized organelles.
Thus I suggest that catabolic and anabolic have evolved separately and
often have separate organelles. (See post of Specific Examples).
Catabolic and anabolic pathways differ.
"Chemical chaos would result if all of a cell's metabolic pathways
were open simultaneously. Imagine, for example, a substance
synthesized by one pathway and broken down by another. If the two
pathways were to run at the same time, the cell would be spinning its
metabolic wheels. actually, the operation of each metabolic pathway is
tightly regulated. Pathways are switched on and off by controlling
enzyme activity....
Even when the enzymes for a metabolic pathway are individually
dissolved, they may be highly concentrated along with their substrates
within specialized organelles of the cell.... If the cell had the same
number of enzymes for respiration , but they were diluted throughout
the entire volume of the cell, respiration would be very inefficient."
Campbell
""Catabolic and anabolic pathways differ. If a metabolite is converted
to another metabolite by an exergonic process, free energy must be
supplied to convert the second metabolite back to the first. This
energetically "uphill" process requires a different pathway for at
least some of the reaction steps.
The existence of independent interconversion routes ... is an
important property of metabolic pathways because it allows independent
control of the two processes. If metabolite 2 is required by the cell,
it is necessary to 'turn off' the pathway from 2 to 1 while 'turning
on' the pathway from 1 to 2. Such independent control would be
impossible without different pathways." Voet, Voet, Pratt. |
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| John Edser... |
| Posted: Fri Oct 23, 2009 5:25 am |
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Tom Hendricks <tom-hendricks at (no spam) att.net> wrote:-
[quote]Catabolic and Anabolic pathways must be separate.
Catabolic and Anabolic are regulated by enzymes.
Enzymes have evolved to specialized organelles.
[/quote]
Catabolic and anabolic pathways, no matter if they are regulated by
different enzymes, or even if they happen to be located within different
organelles within the same fertile form, cannot be independently
selected (possess their own independent OBJECTIVE fitness) within NATURE
any more than your thumb can be independently selected from your
fingers. Metabolic processes are required to biologically cooperate
within the one, same organism to such a high degree of closeness that
they have no other choice other than to share the one, same OBJECTIVE
total Darwinian epistatic fitness. OTOH, as far as Neo Darwinian
SUBJECTIVE fitnesses are concerned, just about anything goes...
The next thing we will be hearing is a model altruistic catabolism
evolving via the independent selection of a selfish anabolism (or the
reverse). This sort of mathematical Neo Darwinian logic is so far
removed from nature it reduces the critical organism concept within
evolutionary theory to become just a population of independent in
fitness genes. IOW it represents an additive in fitness (non epistatic),
massively oversimplified, Frankenstein science in which even metabolic
process are allowed to be modeled as an additive in fitness mosaic of
body parts.
Regards,
John Edser
Independent Researcher
edser at (no spam) ozemail.com.au |
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