You are correct fat can not be directly converted to
glucose, however, it is indirectly coverted to
glucose.

The break down of fat is known as lipolysis.  Only the
triglycerides are the major souce of energy.  To be
used for energy the triglyceride must be broken down
to its basic units of free fatty acids(FFA) The
enzymes that do this are known as lipases.  Once the
FFA are freed from the glycerol(protien coating) its
transfered through the body via the blood. and enters
the muscle fibers depending on the gradient  of FFA in
the blood relative to the muscle tissues.

Once in the mucsle cells the process that results is
called Beta Oxidation and goes like this.  The FFA is
activated with ATP preparing it for catabolism within
the mitochondria.  The carbon chain of the FFA is
broken in half to form units of acetic acid.  Each of
the molucules of acetic acid are then converted to
acetyl CoA.  Enter the Krebs cycle and electron
transport chain.  Need I go any further?

The whole process is termed Gluconeogenesis and is the
process by which fat and protien are broken down and
used for energy

The result of ATP produced by even one molecule of say
palmitic acid is
                                        Direct  Indirect
Fatty Acid Activaction  0       -2
B-Oxidation                             0       35
Kreb cycle                              8       88
-------------------------------------------
                                                8       121
                                                   129
While it takes energy to activate the FFA and free it
from the glycerol the result is more ATP than is
produced by The break down of Glycogen/Glucose

Lipolysis-->Triglycerides-->Acetic Acid-->Acetyl
CoA-->Electron Transport Chain-->ATP

Stricly speaking Fat is not turned into glucose, this
would require the glucose to go through the Krebs
cycle.  This does not happen.  Glucose is broken down
into Pyruvic Acid, Triglycerides are broken down into
Acetic Acid, from that point on eveything is the same
except you get more ATP from the breakdown of the fat
because there is more carbon


The critic is correct, and Neanderthin is
> wrong.  You can't turn
> > > >fats into glucose
> > >
> > > i don't understand that. what storing fats is
> good for if it is not used to
> > > be turned into glucose again.?
> >
> >Your question assumes that stored fat is useful
> only if it can be
> >turned into glucose.  This is false.  The stored
> fat can later be
> >used as fuel, but doing so does not depend upon it
> being
> >converted to glucose.  When stored fat is used as
> fuel, it is
> >used *as fat*.  Again, there is no conversion of
> fat to glucose
> >in the human body.
>
> Stricly speaking, a trygliceride is made up of three
> fatty acids attached to a
> glycerol 'backbone'.   Isnt the glycerol converted
> to glucose?  I seem to
> remember
> that these glycerols can contribute a substantial
> amount of glucose that is
> particularly important when in ketosis.
>
>    Wade Reeser
>
>
> >Todd Moody
> >[log in to unmask]
>

=====
-kb.
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