independent light reactions

Question 1

carbon fixation

(3)

Answer 1

• CO2 is added to RuBP to form a 6C intermediate
• splits into 2 3-phosphoglycerate

occurs 3 times to produce 6 molecules of PGA

Question 2

reduction reaction

(4)

Answer 2

• PGA is phosphorylated to create 6 molecules of 1,3 bisphosphoglycerate
• NADPH is oxidized to NADP+ and the 2 electrons from each of the 6 NADPH reduce 1,3 BPG to G3P
• 6 Pi molecules are released and go back to light reactions to make more ATP

only one of the G3P is used to make organic molecules

Question 3

RuBP regeneration

Answer 3

• the remaining 5 G3P are combined and re arrange to form 3 molecules of RuBP
• 5 mol. G3P x 3 carbons / G3P = 15 carbons
• rearanged to 3 molecules of RuBP — 3 RuBP is 15 carbons

Question 4

why is RubisCo considered on of the most important enzymes on earth

(2)

Answer 4

• it helps in the making of organic molecules that are consumed by many of the worlds organisms
• catalyzes the reactions of CO2 + RuBP to 3-phosphoglycerate

Question 5

how is RuBP regenerated

Answer 5

the calvin cycle

Question 6

exergonic or endergonic

Answer 6

endergonic process that uses the ATP and NADPH produced in the light dependent reactions of photosynthesis