So, we're learning a lot about how our enzymes can be controlled.
We have other things that may assist enzymes that I eluded to
in the past lectures where we have cofactors and coenzymes
that could asist enzymes.
For example, in hemogloblin, we have our alpha and beta subunits
we call hemoglobin, it's inside red blood cells.
And in each of these subunits, there is a heme group.
And that heme group is where we're going to have the oxygen sit.
So in order to get oxygen in there most efficiently,
it really helps if we have an iron molecule.
So that iron molecule is a cofactor in helping oxygen
bind to the heme group inside the hemoglobin.
We could also have coenzymes. Coenzymes, because their enzymes
are proteins, cofactors are non protein, coenzymes are proteins,
and they can also asist.
Here is an example of how the two might come together.
We have our holoenzymes. So maybe the enzymes made of multiple subunits
and holoenzyme is a word we use to describe the holo thing, you know.
And there are different regions of that enzyme.
It has a weird looking active site. That active site is perhaps not
the ideal shape for the substrate that might bind into it
and so we can have another piece of protein or a coenzyme
that comes into the original enzyme and binds to that site.
We may also have a cofactor, like the iron we saw in hemoglobin,
a non protein thing that helps shape the active site
and make it more attractive to the signal molecule
or to the substrate that's going to come and sit in there.
Once that shape is the correct shape, then the substrate can come in,
and the enzyme can continue with its activity.