1 Which of the following cofactors cannot undergo a one elec

1. Which of the following cofactors cannot undergo a one electron reduction?

A. FADH

B. FAD

C. UQ

D. NAD+

E. UQH–

2. What is the purpose of the electron transport chain?

A. to pump electrons out of the matrix

B. to pump protons out of the matrix

C. to bring electrons into the matrix

D. to bring protons into the matrix

E. none of these

3. As a result of the ETC an osmotic difference is created between the matrix and the:

A. cytoplasm

B. matrix

C. nucleus

D. innermembrane space

E. outermembrane

Explain

Solution

1.FAdDand FADH2

2. The purpose of the electron transport chain is

Option B. to pump protons out of the matrix.

The protons are pumped into intermebrane space so that concentration gradient occur compaed to the matriix of mitochondria.

3. ETC develop osmotic difference is between the matrix and the: (Option D.) innermembrane space of mitochondria.

The inner mitochondrial membrane is impermeable to H+ and OH- ions so transport of electrons occur throuh ETC along with translocation of protons (H+) across inner mitochindrial membrane from matrix to the intermembrane space. THe pumping of protons results in electrochemical gradient or proton gradient due to accumulation of more H+ ions on the outer side of the inner mitochondrial than in matrix. The proton gradient due to ETC result in synthesis of ATP from ADP and Pi.