How to calculate kinetics values?

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Hello

The table below shows some kinetics values for two types of the GOD enzyme, the free and the immobilised.

upload_2018-10-21_20-31-9.png


How can I comprehend what these values mean?
I want to know how many grams of substrate are 'converted' per sec per mg of enzyme.
I assume the substrate concentration plays role so I want to be able to incorporate that into the calculations.

Thanks!
 

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  • #2
Borek
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I admit I know next to nothing about enzyme kinetics, just a bit about kinetics in general (not that they are different, just enzyme kinetics uses its own set of assumptions which allows for some specific approximations), but it is up to whoever creates the table to define symbols (unless they are universally understood in the field). Consider consulting the source about their meaning (although Ea is rather obvious).
 
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Vmax units have the term dk-1, any idea what that is?
I would expect to have a unit of time like s-1?
 
  • #5
Ygggdrasil
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Not sure what the dk^-1 is. Presumably this would have to have units of inverse time. Does the source give a definition?
 
  • #6
epenguin
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We often require a student to make more effort to solve a problem. Here we need more effort to tell us what the problem is! We are not told what GOD is, I guess it is nothing transcendental but glucose oxidasae or something.

Maybe this dk-1 is just a misprint? For dt-1 or something.
Vmax Is just the rate of oxidation when the substrate concentration is high (Saturating) - in whatever the units are.

The μ mole/sec/mg protein might possibly be a useful in practical work, but is pretty boring.. More interesting would be to get the Turnover number, the number of catalytic events per second per active site, for which you need to know the molecular mass and number of active sites of the enzymes
.
The Km etc presumably refer to glucose But there are two cosubstrates of an oxidase and presumably it refers to conditions of constant, solution-saturating, oxygen concentration.
 
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