Where do the light-dependent reactions of photosynthesis take place?

Predict how the following conditions would affect the production of O₂, ATP, and NADPH and state whether noncyclic or cyclic electron flow would occur in each:

(1) Only blue photons hit a chloroplast

An investigator exposes chloroplasts to 700-nm photons and observes low O₂ production, but high ATP production. Which of the following best explains this observation?

a. The electrons from water are directly transferred to NADP⁺, which is used to generate ATP.

b. Photosystem II is not splitting water, and the ATP is being produced by cycling electrons via photosystem I.

c. The O₂ is being converted to water as a terminal electron acceptor in the production of ATP.

d. Electron transport has stopped and ATP is being produced by the Calvin cycle.

The following diagram compares the chemiosmotic synthesis of ATP in mitochondria and chloroplasts. Identify the components that are shared by both organelles and indicate which side of the membrane has the higher H+ concentration. Then label on the right the locations within the chloroplast.

<IMAGE>