Electron Flow in Light Reaction

Question 1

Photophosphorylation involves using light energy (photo) to make ATP from ADP (phosphorylation). Choose the correct sequence on how
these steps take place in this process:
I. Synthesis of ATP
II. Light absorption in photosystem II
III. Formation of NADPH
IV. Light absorption in photosystem I

A. II, I, IV, III
B. II, IV, III, I
C. II, I, III, IV
D. II, III, I , IV

Answer 1

A. II, I, IV, III

Question 2

As electrons flow, energy from light is required and thus, involves four electrons aided by an acceptor and a donor. Which pair of molecules assumes this role?

A. NADP+ and H2O
B. H2O and O2
C. NADP+ and 2H+
D. O2 and 2NADPH

Answer 2

A. NADP+ and H2O

Question 3

The energy is used to establish the proton gradient across the thylakoid membrane comes from the ____

Answer 3

Passage of electrons along the ETC of photosystem II.

Question 4

What are the products of the light reactions that are subsequently used by the Calvin cycle?

Answer 4

ATP and NADPH

Question 5

If photosynthesizing green algae re provided with CO2 synthesized with heavy oxygen18O, later analysis will show that all but one of the following compounds produced by the algae contain18O label. That one
is ___

Answer 5

O2

Question 6

What is produced from the light-dependent reactions of photosynthesis that are used in the dark reactions?

Answer 6

NADPH and ATP

Question 7

How is NADP+ and NADPH in the light reaction related?

Answer 7

NADPH is reduced to NADP+

Question 8

What is NOT used by the light independent reactions of photosynthesis?

Answer 8

Rubisco

Question 9

How is the Calvin Cycle different from the light-dependent reactions?

Answer 9

It takes place in the chloroplast

Question 10

Why does the space inside the thylakoid become positively charged during the light-dependent reactions?

Answer 10

ATP synthase pushes H+ ions from the stroma across the membrane into the space.