1. Photosynthesis

2. Light Absorption Sun gives off visible light (ROYGBIV)
Unabsorbed light reflects to our eyes
Most green light not absorbed by leaves
Chlorophyll absorbs sunlight
Absorb mostly reds and blues

3. Prism
White light

4. Which color(s) are being reflected
Which color(s) are being reflected? Yellow Which color(s) are being absorbed? Red, Orange, Green, Blue, Indigo, Violet

5. Which color(s) are being reflected
Which color(s) are being reflected? Blue Which color(s) are being absorbed? Red, Orange, Yellow, Green, Indigo, Violet

6. Which color(s) are being reflected
Which color(s) are being reflected? None…Black is the absence of light Which color(s) are being absorbed? All….ROYGBIV

7. Which color(s) are being reflected
Which color(s) are being reflected? All…ROYGBIV Which color(s) are being absorbed? None

8. Which color(s) are being reflected
Which color(s) are being reflected? Green Which color(s) are being absorbed? Red, Orange, Yellow, Blue, Indigo, Violet

9. The Chloroplast Site of photosynthesis
Thylakoid membranes: light dependent reactions
Stroma (fluid interior): light independent reactions

10. Stomata: pore underneath leaves through which gases enter/exit

11. Photosynthesis Overview
Two Stages
1) Light Dependent Reactions
Photosystems: groups of molecules that capture/transfer energy
Creates: O2, ATP, NADPH
2) Light Independent Reactions
Creates: Glucose

12. Light Dependent Reactions

13. Light Dependent Reactions
Stroma
PSI
PSII
Thylakoid
thylakoid
thylakoid
Granum
thylakoid

14. Light Dependent Reactions
Stroma
Light Dependent Reactions H H H H H H O O O
PSI
PSII
Thylakoid e e e e e e
Step 1:
Chlorophyll in PSII absorbs sunlight and electrons become excited
Thylakoid membrane becomes negatively charged
Starts an “electron transport chain”

15. Light Dependent Reactions
Stroma
Light Dependent Reactions e e H H H H e e e H e H O O O
PSI e e e e e e
PSII
Thylakoid
Step 2 & 3:
Water molecules are broken
H+ pulled into thylakoids
Electrons replace those lost by chlorophyll to keep cycle going
Oxygen waste released

16. Light Dependent Reactions
Stroma
Light Dependent Reactions
PSI e e e e e e e e e
PSII e
Thylakoid e e H H H H H H
Step 4:
Chlorophyll in PSI absorbs sunlight and electrons become excited

17. Light Dependent Reactions
Stroma
Light Dependent Reactions
PSI e e e e e e
PSII e
Thylakoid H e e e H H
NADP H H e H H e H
NADP
Step 5:
Electrons help bond NADP + H to create NADPH (H taxi)
NADPH will be used later

18. Light Dependent Reactions
Stroma
Light Dependent Reactions
PSI e e e e e e
PSII e
Thylakoid e e e H H H H H e H
ATP
synthase
ATP
ATP
ATP
Step 6 & 7:
H+ diffuses into the stroma
H+ helps bond ADP + P to create ATP
ATP will be used later P
ADP P
ADP
ADP P

19. Light Dependent Summary
O2, ATP, NADPH created
NO GLUCOSE CREATED!

20. Light Independent Reactions (Calvin Cycle)
Stroma
Light Independent Reactions (Calvin Cycle)
5C = RuBP C C
CO2
Step 1:
CO2 from the air bonds with a 5 carbon molecule… 6 carbon molecule created

21. Light Independent Reactions (Calvin Cycle)
Stroma
3C = PGAL
ATP C C C
NADP H
3C = PGAL
Step 2:
ATP and NADPH (from light dependent cycle) finally used!
6 carbon molecule broken into two 3 carbon molecules

22. Light Independent Reactions (Calvin Cycle)
Stroma
Light Independent Reactions (Calvin Cycle)
PGAL
PGAL
ATP C C C C
NADP H
PGAL
PGAL C
ATP
PGAL C C C
NADP H
PGAL
Step 2:
ATP and NADPH (from light dependent cycle) finally used!
6 carbon molecule broken into two 3 carbon molecules
Process repeats

23. Light Independent Reactions (Calvin Cycle)
Stroma
Light Independent Reactions (Calvin Cycle)
Glucose
C6H12O6 C C C C C C C C C
5C = RuBP C C C C C
ATP
5C = RuBP C C C C
5C = RuBP C C C
Step 3 and 4:
Some 3 carbon molecules will bond to make GLUCOSE!
Other 3 carbon molecules will recombine to make 5 carbon molecule

24. Light Independent Summary
CO2, ATP, & NADPH create glucose

25. Light Independent Reactions (Calvin Cycle)

26. Your essay question on the next test!
Trace the flow of energy, including ATP, from the sun to your muscles, after eating a green leaf salad.

27. Kobe Kuiz Place these steps in order from start to finish:
A) Electron transport chain creates NADPH and ATP energy
B) 3C molecule broken by ATP into 5C molecule
C) PGAL created when 6C molecule broken down
D) Water broken into H+, e-, and O components
E) Sunlight causes chlorophyll electrons to flow into thylakoid membrane
F) 3C molecule bonds to create glucose
G) CO2 bonds with RuBP

28. Kobe Kuiz Place these steps in order from start to finish:
E) Sunlight causes chlorophyll electrons to flow into thylakoid membrane
D) Water broken into H+, e-, and O components
A) Electron transport chain creates NADPH and ATP energy
G) CO2 bonds with RuBP
C) PGAL created when 6C molecule broken down
F) 3C molecule bonds to create glucose
B) 3C molecule broken by ATP into 5C molecule