1. Video
Where do trees get their mass?-Veritasium (Resources Page)

2. Where Does Photosynthesis Occur?
Leaf Cross Section
Mesophyll
CO2 O2
Vein
Leaf
Stoma
Mesophyll Cell
Chloroplast
Thylakoid
Thylakoid space
Stroma
Granum
Inner and outer membranes
Key Terms
Mesophyll- Green tissue in the middle of the leaf that contains cells with concentrated chlorophyll
Stomata- Tiny holes on the underside of the leaf that allow CO2 to enter and O2 to exit

3. Where Does Photosynthesis Occur?
Leaf Cross Section
Mesophyll
CO2 O2
Vein
Leaf
Stoma
Mesophyll Cell
Chloroplast

4. Where Does Photosynthesis Occur?
Chloroplast
Thylakoid
Thylakoid space
Stroma
Granum
Inner and outer membranes

5. Chloroplast Key Terms
Thylakoid- membranous sac which encloses the thylakoid space and houses much of the machinery that converts light energy to chemical energy. Grana- Stacks of thylakoids Stroma- thick liquid within the chloroplast that the thylakoids are suspended in.

6. Photosynthesis Equation
Becomes reduced
Becomes oxidized

7. Overview of Photosynthesis

8. Overview of Photosynthesis

9. Overview of Photosynthesis

10. Pigments Absorb Light Energy
Sunlight contains energy called electromagnetic energy or electromagnetic radiation.
The visible part is a very small part of the spectrum.

11. Pigments Absorb Light Energy
Chlorophyll is one of the pigments that absorb light energy in plants.
Built into the Thylakoid membrane
Absorb some colors and other colors are transmitted or reflected.

12. Different Pigments in Plants
Chlorophyll a
Participates directly in light reactions.
Absorbs mainly blue-violet and red light.
Reflects green light.
Chlorophyll b
Broadens the range of light absorbed and passes energy to Chlorophyll a to be used.
Absorbs mainly blue and orange light.
Reflects yellow-green light.

13. Different Pigments in Plants
Carotenoids- yellow/orange
Broadens the spectrum of light that can be absorbed and passed to Chlorophyll a to be used in photosynthesis.
Used in photoprotection by absorbing dissipated light that could harm chlorophyll or interact with oxygen and damage cells.
Break down slower than chlorophyll.

14. Photosystems
In the thylakoid membrane, chlorophyll and other pigments and proteins are organized into clusters called photosystems
Photosystems consists of a number of light-harvesting complexes that surround a reaction-center complex.

15. Photosystems
Pigment molecules absorb light and transfer energy until it reaches the reaction-center complex
Then a special pair of Chlorophyll a molecules transfer an excited electron to the Primary Electron Acceptor

16. Photosystems
This transfer of energy is the first step in converting light energy into chemical energy in the light reactions.
Two types of photosystems work together in the light reactions.
Photosystem II
Photosystem I
Connected by an Electron Transport Chain
Differ by the type of light absorbed

18. Photosystems
In the light reactions, light energy is transformed into the chemical energy of ATP and NADPH.
To accomplish this, electrons are
removed from water,
passed from photosystem II to photosystem I, and
accepted by NADP+, reducing it to NADPH.
Between the two photosystems, the electrons
move down an electron transport chain and
provide energy for the synthesis of ATP.

19. Photosystems

20. Light Reaction Products
The products of the light reactions are
NADPH,
ATP, and
oxygen.

21. Photosynthesis

22. Calvin Cycle Called dark reactions or light independent reactions
Produces sugars in the cell by using:
CO2 from air
ATP and NADPH from Light Reactions
Produces an energy rich three carbon sugar called Glyceraldehyde-3-Phosphate (G3P)
G3P can then be used to make glucose and other molecules.

23. Calvin Cycle
Glucose

24. Connection to Light Reactions

25. Steps of the Calvin Cycle
The steps of the Calvin cycle include:
carbon fixation,
reduction,
release of G3P, and
regeneration of the starting molecule ribulose bisphosphate (RuBP).

26. Step Carbon fixation Input: 3 CO2 Rubisco 3 P P 6 P RuBP 3-PGA
Figure 7.10B_s1
Step Carbon fixation 1
Input: 3
CO2
Rubisco 1 3 P P 6 P
RuBP
3-PGA
Calvin Cycle
Figure 7.10B_s1 Details of the Calvin cycle, which takes place in the stroma of a chloroplast (step 1) 26

27. Step Carbon fixation Input: 3 CO2 Rubisco 3 P P 6 P RuBP 3-PGA
Figure 7.10B_s2
Step Carbon fixation 1
Input: 3
CO2
Rubisco 1 3 P P 6 P
RuBP
3-PGA
Step Reduction 2 6
ATP 6
ADP P
Calvin Cycle 2 6
NADPH 6
NADP
Figure 7.10B_s2 Details of the Calvin cycle, which takes place in the stroma of a chloroplast (step 2) 6 P
G3P 27

28. Step Release of one molecule of G3P 6 NADP 6 P 5 P G3P G3P
Figure 7.10B_s3
Step Carbon fixation 1
Input: 3
CO2
Rubisco 1 3 P P 6 P
RuBP
3-PGA
Step Reduction 2 6
ATP 6
ADP P
Calvin Cycle 2 6
NADPH
Step Release of one molecule of G3P 3 6
NADP
Figure 7.10B_s3 Details of the Calvin cycle, which takes place in the stroma of a chloroplast (step 3) 6 P 5 P
G3P
G3P 3
Glucose and other compounds
Output: 1 P
G3P 28

29. Step Release of one molecule of G3P 6 NADP 6 P 5 P G3P G3P
Figure 7.10B_s4
Step Carbon fixation 1
Input: 3
CO2
Rubisco 1 3 P P 6 P
RuBP
3-PGA
Step Reduction 2 6
ATP 3
ADP 6
ADP P
Calvin Cycle 4 2 3
ATP 6
NADPH
Step Release of one molecule of G3P 3 6
NADP
Figure 7.10B_s4 Details of the Calvin cycle, which takes place in the stroma of a chloroplast (step 4) 6 P 5 P
G3P
G3P 3
Glucose and other compounds
Step Regeneration of RuBP 4
Output: 1 P
G3P 29

30. Animation Photosynthesis Animation-McGraw Hill (Resources Page)