In noncompetitive inhibition, why does Vmax decrease?

Question

photon336 · Answer

@Somy @Abhisar

photon336 · Answer

@.Sam.

somy · Answer

because there is no competition for active site so inhibition of an enzyme is easier & more successful
when we deal with competitive one, inhibitor and substrate are competing for the active site of the enzyme, when we increase concentration of the substrate, we are increasing chances of collision between substrate and enzyme, surely with the inhibitor too but overall vmax is more steeply increasing. 
in case of non competitive inhibition, increasing concentration of the substrate only works in favor of the inhibitor, again increasing chances of successful collisions between each other and that includes inhibitor+enzyme collision. Issue is that since that inhibitor will bind strongly to an enzyme once it gets a hold of it, conc of free enzyme to do the job decreases thereby decreasing the vmax

photon336 · Answer

so what's happening is that the enzyme is like being taken out of the reaction in a way. so It can't reach it's V max

photon336 · Answer

so v max  is the maximum velocity the enzyme / substrate can combine? then after that adding more enzyme won't increase the reaction rate?

photon336 · Answer

@Somy

somy · Answer

vmax is a maximum velocity at which a reaction is catalyzed using enzymes

somy · Answer

so it depends on conditions, is there an inhibitor? what kind? how much is substrate concentration?

somy · Answer

http://www.ucl.ac.uk/~ucbcdab/enzass/inhibition.htm this seems like a good source to explain with graphs

somy · Answer

key here is you visualization and logic, we both know that for a reaction to take place we need the enzyme and substrate to collide, with good enough KE, which is successful collision. 
so given that, and also know that one of the inhibitors wants the active site of the enzyme just like a substrate and the other inhibitor can bind to a different section of an enzyme to inhibit it, what can you see?

somy · Answer

and then just analyze the situation with increasing and decreasing concentrations of enzyme, inhibitor, substrate