Greetings. Welcome to this lecture 15 in this Principles of Biochemistry lecture series.
I am Jerry Feigenson,
a professor in the Department of Molecular Biology and Genetics
at Cornell University in the USA.
In the 14th lecture,
you learned some key principles of metabolism energetics,
and more are coming in the future lectures.
You saw in the 14th lecture,
how to think about the stability of molecules,
and in particular, what are high-energy molecules,
and whether reactions tend to occur?
You saw that redox reactions have
an especially important role for all creatures that require oxygen for life.
In this 15th lecture,
you will see how thousands of chemical reactions of metabolism are interconnected,
and we only have very partial knowledge about that.
You will see why cells rely on stored glucose as their energy source.
And glycolysis provides, besides energy,
many useful chemicals for the cell.
We will see the strategy of isomerisation and carbon-carbon bond cleavage in glycolysis.
We will see that Delta G, as opposed to Delta G_0,
Delta G is used to identify
which reaction steps in metabolism are far from equilibrium and regulated.
Then at the end we will see the reaction steps in one enzyme of glycolysis,
glyceraldehyde 3-phosphate, this is the only redox step of glycolysis.