Question

Mobile electronic carriers in ETS in mitochondrial membrane are
A)PQ,PC
B)CoQ,Cyt c
C)PQ,Cyt c
D)PC,CoQ

Answer 1

Hint: The electron transport chain (ETC is a sequence of complexes that transfer electrons by redox (both reduction and oxidation occurring simultaneously) reactions from electron donors to electron acceptors, and combine this electron transfers across a membrane with the passage of protons (H+ ions). Peptides, enzymes, and other molecules are made up in the electron transport chain.

Complete answer:
The I-IV complexes, as well as the ubiquinone and cytochrome c electron transporters, form the mammalian mitochondrial electron transport chain (ETC). Complex I/III/IV, with the substrate being NADH, and Complex II/III/IV, with the substrate being succinic acid, are two electron transport pathways in the ETC. The electron flow is combined with the creation of a proton gradient across the inner membrane and the energy stored in the proton gradient is used by complex V (ATP synthase) to produce ATP.

There are four protein complexes and two mobile carriers of electrons in the electron transport chain (ETC) operating in the mitochondrial membrane. CoQ (coenzyme-Q) is sometimes referred to as Ubiquinone and cytochrome-C (Cyt C).

 CoQ is a compound that is organic. The electrons are collected from the Complex-I and Complex-II by the CoQ and the electrons are transferred to the Complex-III. The Co-Q, since it is hydrophobic, does not leave the inner membrane of the mitochondria.All Complex-III and Complex-IV, another mobile electron carrier called Cytochrome-C works. It is situated on the internal membrane's outer side.

Ubiquinone or coenzyme Q is an organic molecule that can travel freely through diffusion inside the hydrophobic region of the mitochondrial membrane found in the inner mitochondrial membrane. It is thus referred to as the mobile electron carrier and thus transfers electrons to cytochromes that eventually transmits the electrons to molecular oxygen.

Hence, the correct answer is option (B)

Note: A component of aerobic respiration that uses free oxygen as the final electron acceptor of electrons removed from the intermediate compounds in the catabolism of glucose is the electron transport chain. Four large multiprotein complexes embedded in the inner mitochondrial membrane and two small diffusible electron carriers shuttling electrons between them make up the electron transport chain.