Question

Sodium azide is used to inhibit growth of Gram-negative microbes by inhibiting cytochrome oxidase. What role does cytochrome oxidase play in the cell? Why would this inhibit growth (and be so toxic to us)? 

Answer 1

Sodium azide is the inorganic compound with the formula NaN₃ . It is an ionic substance ,is highly soluble in water and is very acutely toxic.

The sodium azide acts as a bacteriostatic by inhibiting cytochrome oxidase in gram negative bacteria .

Function of cytochrome oxidase- the enzyme cytochrome c oxidase or complex IV is a large transmembrane protein complex found in bacteria ,archaea and in eukaryotes in their mitochondria.

It is one of the complex of electron transport chain. It helps in transfer of electron from cytochrome to oxygen in the process and help in generating proton gradient. And then this proton gradient is used in generating ATP. And as we know ATP is very important in conducting all the cell processes.

If complex IV or cytochrome oxidase c is no longer transfer electron(if blocked) the rest of the electron chain will quickly back up and come to halt. If electrons will not longer be pumped out of the matrix and into the intermembrane space.

As the proton already in the intermembrane space flow down their gradient into matrix,they won't replaced causing the gradient to weaken and eventually disappear.

So as a result ATP will not get produced and due to this the organism (in this case bacteria) will die.