Unit 2 - Light Independent Rxn

Question 1

where does the light dependent rxn occur

Answer 1

Thylakoid membrane = chloroplast

Question 2

what is photolysis

Answer 2

splitting of water into O2 and water

Question 3

what did our light dependent rxn produce

Answer 3

ATP
NADPH2
and
O2 (waste)

Question 4

Light Independent RXN

Answer 4

• stroma of chloroplast a series of 11 reactions uses NADPH to reduce co2 into sugar
• endergonic (energy supplied by hydrolysis of ATP)
• Calvin Cycle (11 enzymes catalyzed)

Question 5

Melvin Calvin

Answer 5

• An American biochemist won the 1961 NP for chemistry for discovering the chemical pathway of photosynthesis using c14. he started with CO2 from the atmosphere and ended up as carbohydrates that r the principal food for animals

Question 6

Plants produce…

Answer 6

all organic mol necessary for growth (carbs/ lipids/ proteins/ nucleic acids)

Question 7

Plants need to store…

Answer 7

chemical energy (ATP) produced from light rxn
- more stable
- moved around plant
- saved for a rainy day

Question 8

plant chemical equation

Answer 8

6co2 + 6h20 + light energy =
glucose (c6h1206) +602

Question 9

light rxn

Answer 9

converts solar energy to chemical energy
-ATP = energy
-NADPH = reducing power
what can we now do?
BUILD STUFF

Question 10

CO2 to C6H1206

Answer 10

• co2 v little chemical energy =
  fully oxidized
• c6h1206 lots of chemical energy = highly reduced

Question 11

reduction of co2 to c6h1206 makes?

Answer 11

many small uphill steps
- each catalyzed by specific enzymes
-using energy stored in ATP and NADPH

Question 12

From Light rxn to Calvin cycle

Answer 12

cc = occurse in the stroma of chloroplast and needs products of light to drive synthesis rxn to make (ATP AND NADPH)

Question 13

Calvin cycle 3 phases

Answer 13

1) carbon Fixation
2) reduction reactions
3) regeneration of RuBP

Question 14

Calvin cycle use of CO2

Answer 14

using carbon from CO2 e- from NADPH and energy from ATP the cycle constructs G3P which is used to build glucose and other organic mols

Question 15

Phase 1: carbon fixation

Answer 15

at the beginning of the CC, CO2, an inorganic compound reacts w a mol of ribulose 1-5 bisphosphate (RuBP), a 5c sugar to make 3c mols of 3-phosphoglycreate.

Question 16

step 1 of carbon fixation

Answer 16

co2 from atmosphere is added to ribulose 1,5- bisphosphate (RuBP) which ha 5c forming a 6c mol

Question 17

step 2 of carbon fixation

Answer 17

6c is v unstable and immediately splits into two 3-phosphoglycerate (3PG)

Question 18

Rubisco

Answer 18

• enzyme: RUBP carboxylase/oxygenase
• catalyzes first rxn: fixes carbon
• most abundant protein on earth
  -undergo photorespiration

Question 19

Photorespiration

Answer 19

when rubisco binds O2 instead of CO2 (it slows down the Calvin Cycle and wastes CO2 and ATP)

Question 20

Phase 2: Reductase of G3P

Answer 20

Reduction:
in the second stage, ATP and NADPH r used to ocnver the 3-PGA mol into mol of a 3c sugar,
glyceraldehyde-3-phosphate (G3P)

Question 21

how did phase 2 get its name

Answer 21

bc NADPH donates e- to or reduces, a three-carbon intermediate to make G3P

Question 22

step 1 of phase 2

Answer 22

each mol of 3-PGA receives a phosphate group from ATP, turning into a double phosphorylated mol called 1,3-bisphosphoglycerate (leaving ADP as a by-product)

Question 23

step 2 of phase 2

Answer 23

1,3, BPG mol r reduced. each mol gets two e- from NADPH and loses one of its phosphate group, turning into a 3c sugar called G3P (produces NADP + Pi as a by-product)

Question 24

G3P

Answer 24

important intermediate

Question 25

glucose = ?
lipids = ?
aa = ?
nucleic acids = ?

Answer 25

= carbs
= fats, waxes, phospholipids
= proteins
= DNA and RNA

Question 26

Phase 3: RuBP regeneration

Answer 26

• 5 G3P r rearranged back into 3RuBP w the help of ATP

Question 27

step 1 phase 3

Answer 27

out of every 6 G3P formed, 5 r rycled to from 3 RuBP by + of 3 ATP

Question 28

step 2 of phase 3

Answer 28

6 rotations of CC create 1 mol of glucose. of the 12 G3P mols that r produced in 6 cycles, 10 r used to generate RuBP, and 2 r used to make one glucose

Question 29

Summary of CARBON of Calvin cycle

Answer 29

3 CO2 combine w 3 RuBP acceptors making 6 mols of G3P
- 1 G3P exits to make glucose
- 5 G3P r recycled, regenerating 3 RuBP acceptor mols

Question 30

Summary of ATP of Calvin cycle

Answer 30

9 ATP r converted to 9 ADP (6 during the fixation step 3, during the regeneration step)

Question 31

Summary of NADPH of Calvin cycle

Answer 31

6 NADPH r converted to 6 NADP ( during the reduction steps)

Question 32

plants use of G3P (4)

Answer 32

1) 50% is used for structures (CELLWALL)
2) glucose is converted for energy storage
3) 1/3 is made into starch and stored for leafs use during the night
4) 2/3 is converted to sucrose and transported to rest of plant (roots/ stem/ fruit)

Question 33

supporting a biosphere

Answer 33

on a global scale, photosynthesis is the most important process of life on earth

Question 34

each year photosynthesis… (2)

Answer 34

1) captures 121 billion tons of co2
2) synthesizes 160 billion ton of carbon

Question 35

where in plant cells does the calvin cycle take place

Answer 35

stroma

Question 36

what is the mol that leaves the Calvin cycle to be converted into glucose

Answer 36

G3P

Question 37

whic part of the Calvin cycle would be affected if a cell could not produce the enzyme RuBisCO

Answer 37

none of the parts of the CC could take place

Question 38

reactant or products of CC
1) co2
2) ATP
3) NADPH
4) G3)

Answer 38

1) reactant
2) reactant
3) reactnat
4) both