In photosynthesis, oxygen is produced by:

Which of the following are required for chemiosmosis?

I. A membrane

I. A neutron pump

II. An electron gradient

IV. $\mathrm{ATPase}$

The correct answer is:

Assertion $\left(\mathrm{A}\right):$ In $\mathrm{PS} \mathrm{I}$, the reaction centre, chlorophyll 'a' has an absorption peak at $700 \mathrm{nm}$, hence is called $\mathrm{P}700$, while in $\mathrm{PS} \mathrm{II}$, it has absorption maxima at $680 \mathrm{nm}$ and is called $\mathrm{P}680$.

Reason $\left(\mathrm{R}\right):$ Calvin pathways occur in all photosynthetic plants, it does not matter where they have ${\mathrm{C}}_3$ or ${\mathrm{C}}_4$ pathways and the Calvin cycle described in three stages: Carboxylation, reduction and regeneration.

The correct answer is:

Arrange the path of electrons from water to the phycocyanin in the light reaction.

i) Plastoquinone

ii) Excited ${\mathrm{P}}_{680*}$

iii) Cyt $f$

iv) $\mathrm{Fe}-\mathrm{S}$

v) Pheophytin

vi) Quinone

The correct sequence is

Assertion A: During photophosphorylation protons are transported across the membrane and accumulated inside the lumen.

Reason R: To develop proton gradient, pheophytin transfers electrons to hydrogen carriers instead of electron carrier.

Arrange the given reactions occur in electron transport in correct sequence.

$I)$ Oxygen $\to$ Removes ${\mathrm{H}}_2$ from ETS $\to$ Receives electrons form $ETS$.

$II)$ Ubiquinone $\to$ Oxidized from ubiquinol $\to$ Receives reduced equivalents from ${\mathrm{FADH}}_2$.

$III$Cyt C oxidase $\to$ Reduced by cytochrome $\mathrm{C}\to$ Electron donor for ${\mathrm{O}}_2$ to release ${\mathrm{H}}_2\mathrm{O}$.

$IV)$ Cytochrome $\mathrm{C}\to$ Mobile carrier $\to$ Transfer $e^{-}$ from cyt $\mathrm{b}$ to cyt $\mathrm{c}$ oxidase.