Question

the main electron donor(s) to the electron transport chain of mitochondria is/are

Select one:

a. Oxygen

b. NADH

c. Water

d. FADH2

e. Both b and d are correct

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The main electron donor(s) to the electron transport chain of thylakoids (in chloroplasts) is/are

Select one:

a. Oxygen

b. NADH

c. Water

d. FADH2

e. Both b and d are correct

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During oxydative phosphorylation in mitochondria, the final electron acceptor at the end of the electron transport chain is

Select one:

a. H20

b. NADH

c. O2

d. ATP synthase

e. CO2

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Oxydative phosphorylation takes place in which of the following?

Select one:

a. The inner mitochondrial membrane

b. The mitochondrial matrix

c. The cytosol

d. The outer mitochondrial membrane

e. The smooth endoplasmic reticulum

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Answer 1

The main electron donor in the electron transport chain are NADH and FADH.These are the molecules which are synthesised during Kreb cycle and are oxidised to NAD+ and FAD+.So the right answer is both b and d are correct.

The electron transport chain consists of PSII to PSI .The main electron donor is the water molecule because it is the splitting of water which releases proton,electron to compensate the loss of electron from photosystem II through the electron transport chain carriers like plastoquinone,cytochrome and plastocyanin.This is called Z scheme

There is pumping of proton from stroma in to the lumen.Therefore there is proton gradient which is used for the formation of ATP in presence of light and called as photophosphorylation. Oxygen is the byproduct of splitting of water.Right answer is c) Water

The final acceptor of electron in oxidative phosphorylation in mitochondria is oxygen which receives the electron from the Complex IV and is reduced to water molecule.So the right answer is Oxygen the option c)

The oxidative phosphorylation takes place in the inner mitochondrial membrane resulting in the increase concentration of H+ in the intermembrane space which are translocated back into the matrix through the ATP synthase which causes the formation of ATP from ADP and Pi.Oxidative phosphorylation occurs due to reduction of NADH and FADH equivalents.Right answer is a)

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