Cyanide is an inhibitor of Complex IV of the electron transport chain, i.e., it inhibits the reduction of oxygen to water. Dinitrophenol is a drug that collapses the H+ gradient across the inner mitochondrial membrane.
You are given 2 bottles labeled “A” and “B”. One of them has cyanide and the other has dinitrophenol. You are tasked with identifying which of A or B is cyanide and which one is dinitrophenol.
You are provided with the following items:
- A suspension of live, functioning mitochondria
- A pH-sensitive dye that can permeate both mitochondrial membranes (inner and outer and is red at low pH and blue at high pH.
First, what does it mean to say “collapse the H+ gradient”?
Make a flow-chart to show how you would do an experiment with the items provided to identify which bottle is cyanide and which is dinitrophenol.