Effects of Rotenone and Cyanide on the ETC

The Electron Transport Chain


Rotenone and Cyanide are both inhibitors of the ETC that prevent the production of the proton mtive force (PMF) that allows for the formation of ATP from ADP and an inorganic Phosphate group.

Cyanide binds to the Iron(III) in the Heme group of the Cytochrom oxidase C which is associated with Complex IV. The binding of cyanie prevents the oxidation reaction from taking place so no energy is released to allow the Complex to pump the Hydrogen ions out. Thus, the PMF does not build up and there is not enough energy to allow the H ions to return via ATP synthase and be coupled to the formation of ATP.

Rotenone works in a similar manner but affects Complex I instead.

Rotenone prevents the use of NAH as a substrate so oxidation of the NADH to NAD+ does not take place. No oxidation = no energy to pump the H ions into the intermembrane space leading to a weak PMF that does is not enough to drive the H+ back into the matrix and be coupled to ATP formation.


Therefore, to answer the question posed to us in the tutorial:

Cyanide affects Complex IV

Rotenone affects Complex I

And they both result in your death in high enough doses

This entry was posted in Biochemistry and tagged , , , . Bookmark the permalink.

2 Responses to Effects of Rotenone and Cyanide on the ETC

  1. illuminolist says:

    πŸ˜€ @R2D2 πŸ™‚
    great post, amrita

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s