The next reaction of the pathway
is where we start to create ATPs.
In this reaction 1,3-bisphosphoglycerate is converted
into a molecule called 3-phosphoglycerate,
and this is a pretty straight forward reaction.
You see the phosphate on
position 1 on the left
being removed and transferred to ADP
to make ATP by the enzyme
Now this reaction is interesting in the sense as
what we call a substrate level phosphorylation.
A substrate level phosphorylation
occurs when a high energy molecule
transfers a phosphate onto ADP to make ATP
which is exactly what you have seen here.
Now many people think mistakenly that this
is the way most ATPs is made in the cell,
by simply having a high
energy molecule to transfer.
It doesn't occur that way. And in fact most of the ATP in
cells is made by a process called oxidative phosphorylation.
This is an unusual reaction in a
sense that ATP is made directly.
We will see another one of
those later in glycolysis.
The delta G zero prime for this reaction
is very energetically favorable,
meaning -18.9 kJ/mol. It moves
very strongly to the right
and since we are making an ATP what that
tells us is that there is a lot energy
in 1,3-bisphophoglycerate in order to make
this happen so efficiently.