Question

Members of electron transport chain are present in
A) Mitochondrial matrix
B) Intermembrane space
C) Inner mitochondrial membrane
D) Outer mitochondrial membrane

Answer 1

Hint: Electron transport chain is an important mechanism in cells which is responsible for the production of energy molecules such as ATP by transfer of electrons from donor molecules within mitochondria. This is the reason mitochondria is known as the powerhouse of the cell.

Complete answer:
Mitochondria is a double layered organelle where it consist of outer membrane which has several receptor protein and along with membrane lipids, the receptor proteins includes several Complexes called as (transporter of inner mitochondrial membrane) TIM and (transporter of outer mitochondrial membrane) TOM, these proteins are only responsible for the import of several proteins which have signaling activity. Anyways these proteins are not involved in the electron transport chain.

Intermembrane space has several protein complexes such as TIM and TOM complexes. Inner mitochondrial membranes consist of both transporter complexes and also have all the complexes of the electron transport chain. There are four complexes which are involved in the electron transport chain namely complex I, complex II, complex III and complex IV. Only complex two called succinate dehydrogenase occupies most of its region in the mitochondrial matrix but is found associated with the inner mitochondrial membrane as they are also involved in Krebs cycle of TCA cycle.

Hence the correct answer is option C.

Note: Electron transport chain is a series of protein complexes that are involved in transport of electrons from NADH (nicotinamide adenine dinucleotide hydrogen) and FADH2 to oxygen where proteins are transferred intermembrane space from mitochondrial matrix by the reduction of one water molecule.