Question

Ezymes:
Why is K_M intrinsic and V_M not?

What does intrinsic mean?

K_M = Michaelis-Mentin constant, V_M = V_max

Answer 1

"intrinsic" means that is the property or characteristic comes naturally, and not dependent on environmental conditions. Velocity is not intrinsic to an enzyme because it depends on the concentration of substrate present. Km is intrinsic because it's dependent on how an enzyme and substrate interact with one another.

Answer 2

Do I understand this correctly:
So that means that Km only depends on the enzyme and substrate; there are no other factors that influence it - it is "constant". = INTRINSIC
Whereas velocity has a lot of factors that can influence it. = NON-INTRINSIC
?

Answer 3

more or less, there are other factors that influence it (T, pH, as all biological processes). Velocity is dependent on the substrate concentration, while Km is not.

Answer 4

Is substrate concentration the deciding factor for intrinsicity?

Answer 5

Or rather, the dependency thereon?

Answer 6

hmm we'll "intrinsic" means that it's "from within", as in natural, innate. In this circumstance the dependence on [S] is what differentiates between them.


velocity changes as a function of [S], while Km is a fixed value independent of [S].

Answer 7

but i wouldn't go as far as saying that Km is not dependent on any other factors.

Answer 8

Ah I see what you mean
Thanks for the help!

Answer 9

no problem ! glad i could be of assistance