Question

In the ETC, electron from ubiquinone are transfered to

• A. Complex I
• B. Complex II
• C. Complex III
• D. Complex IV

Answer 1

The correct option is C Complex III

The electron transport chain is located on the inner membrane of the mitochondria.
The electron transport chain uses the electrons from electron carriers to create a chemical gradient that can be used to power oxidative phosphorylation.
There are four protein complexes (labeled complex I-IV) in the electron transport chain, which are involved in moving electron.
Complex I receives electrons from NADH and establishes the hydrogen ion gradient by pumping four hydrogen ions across the membrane from the matrix into the intermembrane space.
Complex II receives FADH₂ , which bypasses complex I, and delivers electrons directly to the electron transport chain.
Ubiquinone (CoQ) accepts the electrons from both complex I and complex II and delivers them to complex III.
Complex III pumps protons through the membrane and passes its electrons to cytochrome c for transport to the fourth complex.
Complex IV receives electron from cytochrome c and reduces oxygen.