Question

Electron transport system occurs in
A. Outer membrane of mitochondria
B. Cristae of mitochondria
C. Matrix of mitochondria
D. Oxysomes.

Answer 1

Hint: The cellular respiration is the steps of different processes that take place in the cells and lead to the formation of ATP or the energy molecules. The ATP are the energy molecules and they are utilized to perform all the different functions of the body. The final step of cellular respiration which produces ATP is known as electron transport chain.

Complete answer:
-The series of different complexes that transfers electrons from the electron donors to the acceptors through the redox reactions and further, couples the transfer of protons across a membrane is called an electron transport chain. In this process, redox or the processes in which simultaneous reduction and oxidation takes place occurs. The energy from the redox reactions create an electrochemical proton gradient and it causes the synthesis of the ATP molecules. The flow of electrons ends with the molecular oxygen in the aerobic respiration. In this type of respiration, the final acceptor of the electron is oxygen. But in the anaerobic respiration, the final acceptor is not oxygen but it is replaced by the sulfate.
-The electron transport system takes place in the cristae present in the inner membrane of the mitochondria. Cristae are the infoldings of the inner membrane of the mitochondria and it aids in the cellular respiration. It contains a number of cytochromes and enzyme ATP synthase. The electrons transfer into the electron transport system in the cristae and pumping of hydrogen ions creates an electrochemical gradient and as a result oxidative phosphorylation of the ADP into ATP takes place.
Matrix of mitochondria is the space that is present within the membrane. It contains DNA, ribosomes, cofactors and several enzymes that facilitate production of ATP molecules.
-The outer membrane of the mitochondria covers the complete structure of the mitochondria and contains a large number of integral membrane proteins which are known as the porins. It also contains a large number of different functional enzymes.
-Oxysomes are found in the inner membrane of the mitochondria. These particles take part in the oxidative phosphorylation process of conversion of ADP into ATP. The stalk part of the oxysomes bear coupling factors which contain ATP for synthesis of ATP.

Hence, the correct answer is option (B).

Note: The electron transport system occurs in the cristae which are infoldings of the inner membrane of the mitochondria. The cristae contain several enzymes that facilitates to create a electro potential gradient and finally oxidative phosphorylation takes place and ATP molecules are synthesized.