Cells are control freaks; because
they have to be control freaks.
If they don't manage the chaos, the
biochemistry going on inside of them,
then they are likely to run out of energy or not
have the energy they need in a critical circumstance.
The way in which cells manage their biochemistry
is through the phenomenon known as metabolic control
and that will be the subject of this talk.
In this presentation, I will go through
first a background on the process
and then talk about mechanisms
of controlling enzyme activity.
These include allosterism, covalent modification
and control of enzyme synthesis or gene expression,
as we have talked about before.
Now metabolic control is essential. But it's
important that we have our terms in agreement.
The metabolic control that I am referring
here to, refers to the mechanisms
that a multicellular organism uses.
So it's not the way that we breathe and it's not
the way we run. But it's the way that our body
response to the needs that's placed upon it.
Metabolic control occurs at the cellular level;
because, that's where all living processes occur.
But it's manifested at the
organismal level, as we shall see.
The cues for metabolic control may arise in
the brain, as part of the conscious process,
or it may be rooted in physiology
so, some examples of that.
Adrenalin is something the fight or
flight response that's initiated.
Its initiate as part of an
awareness that our brain becomes
and this gives us an hormonal response.
The cori cycle by contrast is an
unconscious process that's managed
between our liver and our muscle
in response to exercise.