Question

A large agricultural chemical company is testing a new experimental pesticide. An unfortunate side effect in plants treated with this new product is a decrease in NADPH production in the chloroplasts. (Interestingly, reduction of NAD+ to NADH in the mitochondria is unaffected.) Given this observation, which of the answer choices would you expect to observe in the chloroplasts of these plants?

a. Increase in 3.phosphoglycerate levels and a decrease in RuBP levels
b. a decrease in 3.phosphoglycerate levels and an increase in RuBP levels
c. an increase in glyceraldehyde-3-phosphate levels
d. an increase in 3-phosphoglycerate levels and an increase in RuBP levels

Answer 1

Answer:

The correct answer is a increase in 3-phosphoglycerate levels and a decrease in RUBP levels.

Explanation:

NADPH is a reducing equivalent that is produced during light reaction of photosynthesis.The NADPH that is produced during light react is utilized in the dark reaction.

  A decrease NADPH formation in the chroloplast will in turn decrease the formation of PGALD from phosphoglyceric acid(PGA).Some PGALD are used in the regeneration of ribulose bis phosphate(RUBP).

  From this point of view it can be stated that decrease in NADPH level decreases PGALD level which in turn decreases RUBP levels.

  As NADPH production is decreased in the chloroplast more phophoglyceric acid or 3-phosphoglycerate will accumulate thus the cellular level of PGA is increased.