1. Chpt. 10 Photosynthesis

2. Concept of Photosynthesis
YOU
For Now…

3. As long as plants have leaves & a light source…
they are making glucose

4. Glucose is a good thing!

5. And we are awfully glad about that!!!

6. 6 CO H2O ---> C6H12O6 + 6 O2
+ENERGY
Requires:
Chlorophyll
Light

7. But what if a plant doesn’t have a “typical” leaf?

8. But what is it about the STRUCTURE of a leaf… that allows its FUNCTION to be to produce glucose?

9. Leaves are ORGANS

10. ORGANS are made up of TISSUE

11. Three Tissue Types
Dermal
Ground
Vascular

12. Three Tissue Types Dermal Ground Vascular
storage, support, photosynthesis
outside covering/ protection
prevents H2O loss
Bundle sheeth

13. Three Tissue Types Dermal Ground Vascular
storage, support, photosynthesis
long distance transport between roots & shoots/
support
outside covering

14. Location of photosynthesis:
Mesophyll- interior leaf (ground tissue)
1 mesophyll cell has chloroplasts !

16. gas for photosynthesis:
Stomata- found in outside covering (dermal tissue)
where CO enters
where O exits

17. Three Tissue Types Dermal Ground Vascular outside covering/ protection
prevents H2O loss

18. Slight Differences with MONOcots

19. Stomata are flanked by guard cells

20. Stomata are flanked by guard cells

21. reactant for photosynthesis:
Roots - where H2O enters / travels through xylem (vascular tissue).

22. PHOTOSYNTHESIS 6H2O + 6CO2--> C6H12O6+6O2 roots in stomata
in chloroplast
out stomata

23. Where do the atoms go?

25. one chloroplast
Lets dissect this

26. What is going on?

27. Too Hot
Too Cold

28. one chloroplast

31. P I G M E N T Porphyrin ring: light-absorbing
CH3
in chlorophyll a P I G M E N T
CHO
in chlorophyll b
Porphyrin ring:
light-absorbing
“head” of molecule; note magnesium atom at center
Hydrocarbon tail:
interacts with hydrophobic
regions of proteins inside
thylakoid membranes of chloroplasts; H atoms not shown

32. What happens when pigments absorb light?
Excited
state e–
Heat
Energy of electron
Photon
(fluorescence)
Photon
Chlorophyll
molecule
Ground
state
Excitation of isolated chlorophyll molecule

33. Photosynthesis

34. Light Reaction
&
Dark Reaction
(Calvin Cycle)

35. thylakoid
membrane
stroma

36. Go to the other show

39. Chemiosmosis Model
The chloroplast produces ATP in the same manner as the mitochondria in Respiration.
Light energy is used to pump H+ across a membrane.
When the H+ diffuses back, ATP is generated.

40. Chemiosmosis Model H+ are pumped into the thylakoid space.
ATP and NADPH are made when the H+ diffuse into the stroma.

42. NADPH

44. Solar E. --> Chemical E.:
Light Reaction overview:
Solar E. --> Chemical E.:
Chlorophyll absorbs light E.
water is split into H+ & e-

45. Solar E. --> Chemical E.:
Light Reaction overview:
Solar E. --> Chemical E.:
Chlorophyll absorbs light E.
2) NADP+ bus “carry” H+, and e-
--> from water.
Light is used to reduce NADP+ to NADPH.
NADP+
NADPH

46. Light Reaction overview
Solar E. --> Chemical E.:
3) Photophosphorylation Light energy generates ATP
via. addition of a phosphate to ADP

47. Uses NADPH and ATP from light reaction
Calvin Cycle aka. Dark Reaction
Uses NADPH and ATP from light reaction
Carbon Fixation - Incorporates the carbon from CO2 (from air), into glucose via. E. from ATP and NADPH.
NADPH