[vickyr]

Hello

I need to convert V max (o.d. units/min/ o.o5 ml of enzyme used) to umols NAD used/min/mg

ethanol+nad+ -> products


To be honest I have no idea how od units can be related to umols

Can anyone give me at least any ideas about this question!!

I am struggling with my assigment ((
thank you!!

[Corribus]

Try Beer's law, which related the absorbance of a material to its concentration. But you'll need the extinction coefficient.

http://en.wikipedia.org/wiki/Beer%E2%80%93Lambert_law

(I'm assuming OD = optical density and you're doing a UV-vis expt.)

[vickyr]

Try Beer's law, which related the absorbance of a material to its concentration. But you'll need the extinction coefficient.

http://en.wikipedia.org/wiki/Beer%E2%80%93Lambert_law

(I'm assuming OD = optical density and you're doing a UV-vis expt.)

thank you.

I am provided with E but for the NADH, if I calculate concentration for NADh , does it mean that it is going to be the initial concentration of NAD that was used?? (NADh and NAD are 1:1 ratio in the equation)

[vickyr]

oh sorry, i confused myself, nad+ and nadh is the same thing 

[vickyr]

I calculated NAD moles from the beer lambert law, using vmax value.

Also, i was giving initial concentration of nad in the solution, and it came out to be a larger number than from the first calculation. So it means that not all of NAD was used. So the calculation via beer law gave me how much of NAD was used...

the question is : in the case of vmax, connvert your results to umolf os nad used/min/mg...

the only results i have are vmax and km.

I think I just do not understnad what they want from me in this part...

I calculated the mols of NAD used, so what's next?? it can't be it, there are 10 marks for this question!

thank you for any help and clues!

[Corribus]

Your post formatting is making it very hard for me to understand what you're doing. Why don't you describe the whole experiment in more detail, being a clear as possible. If your assignment is asking specific things, provide the questions here verbatim.

[Babcock_Hall]

oh sorry, i confused myself, nad+ and nadh is the same thing 

No, they are not.  NADH is the reduced form of NAD, and only one of them has a significant absorbance at 340 nm.  Can you provide the molar absorptivity you were given?  Once we have this nailed down the problem is quite easy.