Question

Determine whether the following statements describe Cell Respiration (C), Photosynthesis (P), Both (B), or None (N).

a. Uses a proton gradient to create ATP.

b. Uses byproducts to oxidize NADH to NAD+ for reuse.

2. The thylakoid space of the choloroplast is:

a. More acidic than the stroma

b. More basic than the stroma

c. Hypotonic to the stroma

d. At equilibrium with the stroma

e. Full of electrons from the stroma

Answer 1

1

a. Answer is 'B'.

Because both the cell respiration and photosynthesis uses a proton gradient to synthesise ATP., but their locations are different.

b. Answer is 'A'.

Because in cell respiration by the end of the citric acid cycle several molecules of NADH+ are formed from NAD+. Hence in order to reuse the NAD+ they have to be synthesized again. this is done by the oxidation of NADH

2.

a. The thylakoid space contains more protons than stroma, so it is more acidic than stroma.

b. The thylakoid space is less basic than stroma as it contains more protons than the stroma.

c. Thylakoids contain more aqueous phase, hence they are hypotonic to stroma.

d. They are not at equilibrium with the stroma, but when ever the concentration of the protons increases due to the photolysis of water, these protons will move out of the thylakoid to maintain the proton concentration.

e. The electrons are produced by the photolysis of water. The produced electrons move to the photosystems of the thylakoid membranes. hence electrons move from granum only but not from stroma, as the photolysis centres are located in the grana thylakoids but not in the stroma.