enzyme kinetics absorbance vs time?

Question

every site online talking about this is 99% some school thing

i'm good with math and it's probably incredibly simple
but
i don't understand how to turn absorbance vs time data into usable information
every thing i read on it lightly talks about it and then goes straight to the other equations
i've yet to see what exactly they are doing with this

i'm pretty sure i believe it has something to do with the slopes
but i need to actually see it done out in as many steps

i don't know why it's mystifying me so much
i know for nonlinear plots i should find the tangent buti was told just find the slope at a flat point haha
but a 2nd order regression line fits perfect and i wouldn't mind relating that into it
but
first things first
my retardedness at seeing the connection beyond this

i meant by the first sentence that they casually skip all the important steps
everybody talks about the same equations in the same way
that's great
but how do i make absorbance into Km and Kcat and [S] and [E] etc.

Answer 1

The key idea is that if you can find an absorbance that is proportional just to the concentration of one of the reagents (either a reactant or a product), the way that this absorbance changes with time tells you how fast the concentration of that material changes with time.

This will give you a curve, the shape of which will depend on the kinetics involved.

There are very many ways of analysing these data. One common method is to look at the initial slope (as you correctly say, the slope of the initial tangent) under conditions of different concentration of one of your reactants. If, other things being equal, this slope is proportional to the concentration of the reactant you are changing, then the reaction is first order in that particular reactant, and so on.

I am not sure that this answers your question. If you are looking at anything more complicated, such as how the curve develops over time, you will need to go into the math a lot more deeply than I have here.

Hope this helps!