enzyme activity, please help

[Fa23]

can an enzyme have a negative activity? i had to do this lab and the values i got produce a negative value for activity. so i will just list here a few values that give a negative activity

Optical Density at 0 time, OD after 60s
0.91, 0.92
0.91, 0.93

to find activity you do the following:

(OD at 0 time - OD after 60s)/0.001

but doing this yields a negative value for the enzyme activity, is that okay?

thanks

[canalon]

(OD at 0 time - OD after 60s)/0.001

Here is your mistake.
I assume that your enzyme activity cause an increase of OD so if you want to measure how much the OD has increased you sure got it the wrong way...

[Fa23]

got it the wrong way...

so just flip it around...thats fine and all for this set but the rest of the values are not increasing, either they are steady or they are actually lower than O.D at time 0

[Deat]

Maybe there was human error when collecting the results, in any case, completley restart your equations and keep a log of your equations so that you can quickly identify the error. This would be the best way as it would help prevent future errors.

[JackBean]

actually, the absorbance could decrease as well, if the color substance was consumed For example the cytkinin oxidase/dehydrogenase may be measured by decoloration of electron acceptor DCPIP

[Trevorwin]

Hello!! and how can enzyme inhibitors irreversibly inactivate enzymes??

[JackBean]

by denaturation, binding to crucial residues etc.