PHOTOSYNTHESIS - 20-09-23

The net energy outcome of cyclic phosphorylation is –

• (a) ATP + NADPH₂

• (b) ATP

• (c) Sugar

• (d) NADPH + H⁺

Mutation that inactives cytochrome system would –

• (a) Inhibit movement of electrons from PSI to PSII

• (b) Inhibit movement of e^– from PSII to PSI

• (c) Promote NADPH ⁺ H⁺ formation

• (d) Promote photolysis of water

In Z-scheme of photosynthesis which one(s) is involved?

• (a) PSI

• (b) PSII

• (c) e^– carriers

• (d) All

In Z-scheme which one(s) is / are formed?

• (a) ATP

• (b) NADPH₂

• (c) O₂

• (d) All

Phosphorylation occurs in –

• (a) Mitochondria

• (b) Chloroplast

• (c) Both

• (d) Cell wall

Electrons excited by absorption of light in PSI are transferred to the primary acceptors, and therefore must be replaced. The replacements come directly from –

• (a) NADP

• (b) ATP

• (c) PSII

• (d) Water

What does “PSII splits water” mean?

• (a) Water is broken into monomers

• (b) A condensation reaction occurs

• (c) Water is reduced to yield hydrogen gas

• (d) Water is oxidised to yield protons, electrons and oxygen

If green plant cells are incubated with O¹⁸-labelled CO₂, what molecule will become radioactive as the cells are exposed to light?

• (a) ATP

• (b) Water

• (c) Sugar

• (d) O₂

If green plant cells are incubated with O¹⁸-labelled water, what molecule will become radioactive as cells are exposed to light –

• (a) O₂

• (b) CO₂

• (c) H₂O

• (d) Sugar

Photolysis of a water molecule yields

• (a) 2 electrons and 4 protons

• (b) 4 electrons and 4 protons

• (c) 4 electrons and 2 protons

• (d) 2 electrons and 2 protons