The document discusses cyclic and non-cyclic photophosphorylation and the light-dependent and light-independent reactions of photosynthesis. In the light-independent or Calvin cycle, carbon dioxide is fixed by the enzyme rubisco to the 5-carbon molecule RuBP. This forms a 6-carbon compound that splits into two 3-carbon phosphoglycerate molecules. These are reduced using ATP and NADPH produced in the light-dependent reactions to form triose phosphates, which can regenerate RuBP to restart the cycle or be converted into glucose.

1. Cyclic and Non-cyclic
photophosphorylation
http://highered.mcgraw-hill.
com/sites/9834092339/student_view0/chapter8/cyclic_and_noncyclic_photophosp
horylation.html

2. Light independent reaction
aka Dark Reaction aka Calvin Cycle aka Carbon Fixation Reaction
(k) outline how the products of the light dependent stage are
used in the light independent stage (Calvin cycle) to produce
triose phosphate (TP) (reference should be made to ribulose
bisphosphate (RuBP), ribulose bisphosphate carboxylase
(rubisco) and glycerate 3-phosphate (GP), but no other
biochemical detail is required);
(l) explain the role of carbon dioxide in the light-independent
stage (Calvin cycle);

3. Chloroplast
Photosynthetic
electron-transfer
reactions in
thylakoid
membrane
ATP NADPH
Carbon-fixation
reactions in
stroma
Sugars, amino
acids and fatty
acids
Water
Carbon
dioxide
Oxygen
+
Cytosol
LDR
LIR

4. Word ladder
• Toad
• ----
• ----
• ----
• ----
• ----
• ----
• ----
• ----
• Frog
• Toad
• (street)
• (leaf through)
• (toward the back)
• (phobia)
• (achievement)
• (level or smooth)
• (banner)
• (whip)
• Frog
• Toad
• road
• read
• rear
• fear
• feat
• flat
• flag
• flog
• Frog

5. Phase one – carbon fixation
Ribulose bisphosphate
carboxylase (RuBisCo)
Ribulose bisphosphate
(RuBP)
(aka ribulose biphosphate)
(aka ribulose 1,5 bisphosphate)
2X
Glycerate 3-
phosphate
(GP)
(aka 3-phosphoglycerate)

6. Phase two – reduction (part one)
Glycerate 3-
phosphate
(GP)
(aka 3-phosphoglycerate)
1,3-
bisphosphoglycerate
(GP)

7. Phase two – reduction (part two)
Triose
Phosphate (TP)
(aka glyceraldehyde-3-phosphate)
(aka G3P)
1,3-
bisphosphoglycerate
(GP)

8. Regeneration Several steps
Triose
Phosphate (TP)
(aka glyceraldehyde-3-phosphate)
(aka G3P)
Ribulose 5-phosphate

9. Return to the start
Ribulose bisphosphate
(RuBP)
(aka ribulose biphosphate)
(aka ribulose 1,5 bisphosphate)
Ribulose 5-phosphate

10. Glycerate 3-phosphate
1. Carbon
fixation
Calvin Cycle/LIR
2. Reduction
6x Triose phosphate
1x Triose
phosphate
5x Triose
phosphate
3. RuBP is
regenerated
from triose
phosphate
Glucose

13. Glycerate 3-phosphate
1. Carbon
fixation
Calvin Cycle/LIR
2. Reduction
6x Triose phosphate
1x Triose
phosphate
5x Triose
phosphate
3. RuBP is
regenerated
from triose
phosphate
Glucose

14. The role of Carbon Dioxide

15. Useful Animation
• http://www.science.smith.edu/departments/
Biology/Bio231/calvin.html
• http://highered.mcgraw-hill.
com/sites/007337797x/student_view0/ch
apter7/animation_quiz_-
_how_the_calvin_cycle_works.html

16. Summary test…
• The light independent reaction is also
known as the (1) cycle. In the process,
carbon dioxide combines with a 5-
carbon compound called (2) to form a 6-
carbon intermediate that immediately
splits into 2 molecules of (3). By the
addition of (4) and (5) formed in the (6)
reaction, each of these molecules is
converted into a (7) molecule. These
combine to form a (8) sugar that can
then be made into starch by a process
called (9).

17. Glycerate 3-phosphate
1. Carbon
fixation
Calvin Cycle/LIR
2. Reduction
6x Triose phosphate
1x Triose
phosphate
5x Triose
phosphate
3. RuBP is
regenerated
from triose
phosphate
Glucose
Can be used to make
carbohydrates, lipids
or amino acids

19. Cyclic photophosphorylation