system
Given the following post, respond as if you're commenting on Reddit:
human
When people typically die from poisons or toxins that work as inhibitors for vital enzymes (ex. cyanide), how does a relatively small concentration of the poison/toxin completely disrupt a much larger network of enzymes so quickly?

For instance I am familiar that cyanide poisoning  works by permanently inhibiting cytochrome C oxidase for example. But when someone ingests a tiny capsule of cyanide, it is enough to affect enough of the enzymes so quickly that the person dies instantly. 

How is this possible?
First of all, isn't there way more cytochrome C oxidase enzyme molecules in the body compared to the cyanide molecules in the capsule?  Even if it is very readily absorbed, by these enzymes, wouldn't the reaction taper off at some point being that the cyanide would be the limiting factor? 

Or do these molecules work by denaturing the enzymes and then detaching and moving on to the next enzyme?
gpt
It has a lot to do with relative concentration. Lets say you take in a gram of cyanide and it all gets into your blood. You have about 5 liters of blood at any time, and cyanide has a molecular weight of about 27 g/mol. Therefor your blood becomes about 7.5 mM cyanide. 
Cyanide is an irreversible enzyme inhibitor-- once it complexes with cytochrome C oxidase it inhibits it forever.
Now consider the number of cytochrome C oxidase enzymes in a body- lets lay maybe 1000/mitochondria so maybe ~50000/cell * 60 trillion cells -- on the order of 10^18 enzymes in your body. We just calculated though that the number of cyanide molecules was on the order of 10^22-- if we look at it as a ratio cytochrome c oxidase is 0.000005 as concentrated as cyanide. That means that the rate limiting steps are the diffusion rates of the cyanide from the stomach to the blood, blood to intersticium, intersticum to cell interior, and cell interior to mitochondria, etc.

That's a very rough calculation, but you get the idea that in fact inhibitor is in far excess of enzyme.