1. 11/5/14 Notes over Photosynthesis
Complete and turn in ATP lab DUE by EOC
CW/HW on photosynthesis

2. 8.2 Photosynthesis
Pages

3. LEQ: How is energy, which ultimately comes from the sun, transformed into useable energy?

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More on ATP
Cells Have Enough ATP To Last For A Few Seconds
ATP must constantly be made
ATP Transfers Energy Very Well
ATP Is NOT Good At Energy Storage
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Glucose
Glucose is a monosaccharide
C6H12O6
One Molecule of glucose Stores 90 Times More Chemical Energy Than One Molecule of ATP
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6. Photosynthesis
Photosynthesis is the process of turning light energy into chemical energy!

7. Chemical Equation

8. Photosynthesis Photosynthesis occurs in TWO phases.
Light-dependent reactions
Light-independent reactions (dark reactions)

9. Remember the “reactants”…….
Carbon Dioxide (CO2)
Water (H20)
Energy (sunlight)

10. Where do the reactants come from?
CO2 (a gas) is in the atmosphere and enters the plant through small openings on the back of leaves called stomata.
The stomata is where gas exchange occurs. CO2 in; O2 out

11. Where does everything come from?
Water (H20) comes from the soil absorbed by the plants roots.

12. Where does everything come from?
Light energy comes from the sun and is captured by chloroplasts.

13. Chloroplasts
Chloroplasts capture light energy and are found mainly in the LEAVES.

14. !REVIEW! What are the 3 reactants and how do they get into a plant?
WATER----The roots
Carbon Dioxide---The stomata
Light---The chloroplast.
Is photosynthesis catabolic or anabolic??

15. What organelle does photosynthesis take place in?
Chloroplast

16. Inside the chloroplast.
thylakoids – saclike photosynthetic membranes
grana – stacks of thylakoids
stroma – space outside the thylakoids

17. Energy from the sun travels to Earth in the form of
The spectrum of visible light
Energy from the sun travels to Earth in the form of
light. Sunlight is a mixture of different
wavelengths of light – many of these are visible
to your eyes.

18. How plants obtain energy
Thylakoids have light-absorbing colored molecules called PIGMENTS
Chlorophyll a & b = blue/green
Xanthophyll = yellow
Carotenoids = orange/red
Anthocyanin = red/purple

19. The most common pigment is chlorophyll, which gives plants their green color.
Plants don’t need green light to make food, so it is reflected
– which is why plants are green!

20. Plants absorb red and blue light from the sun to make food
during photosynthesis
Plants don’t need green light to make food, so it is reflected
– which is why plants are green!
So…the best wavelengths of light for plant growth are
red and blue
while the worst wavelength of light for plant growth is
green.

21. Ok… now we have all the reactants….Lets make some SUGAR!!
up!!

22. The Two Phases of Photosynthesis
Phase I - Light Dependent Reaction (occurs in the thylakoids)
Light energy is absorbed and TRANSFORMED to chemical energy (ATP and NADPH molecules)
Rember Chemical energy is ATP!!

23. Light Dependent Reaction
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24. Light Dependent Reaction
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25. Video Clip Explaining Phase I of Photosynthesis – Light Dependent Reactions

26. At the end of Phase I, the plant has made ATP (energy)
What you NEED to Know!
At the end of Phase I, the plant has made
ATP (energy)
NADPH (electron carrier)
O2 (oxygen)

27. Phase II – Light Independent Reaction (or the Dark Reaction/Calvin Cycle) (occurs in stroma)
NADPH and ATP that were formed during light dependent reactions are used to make glucose

28. How plants transform energy
Calvin Cycle converts carbon dioxide into sugar using the NADPH & ATP energy from the light-dependent reactions.
The enzyme Rubisco also helps!

29. Light Independent Reaction (The Dark Reaction) (Calvin Cycle)
ATP and NADPH contain a high amount of energy, but are short stores (no longer than a few minutes).
So plants use the ATP and NADPH to build GLUCOSE which can be stored for a longer time.

30. The Calvin Cycle Does not require light.
6 carbon dioxide molecules are required from the atmosphere
ATP & NADPH powers the cycle

31. Not On FIB write down
The Enzyme Rubisco helps build the glucose molecule during the Calvin cycle.

32. Reactants & products
The Calvin Cycle uses 6 molecules of CO2 to produce a single 6-Carbon sugar molecule called glucose.
Uses for sugars include: form starches & cellulose. When other organisms eat plants, they can also use the energy stored in carbohydrates.

33. And Now a boring person explaining it

34. Summary of Photosynthesis
Light Reactions
Dark reactions (Calvin cycle)
Inputs:
Light
Water
Outputs:
ATP
NADPH
Oxygen (O2)
OCCURS IN THYLOKOID
Inputs:
◦ ATP
◦ NADPH
◦ CO2
Outputs:
◦ Sugars
OCCURS IN THE STROMA

35. Summary
Light reactions Calvin Cycle
Stroma
Thylakoid
Glucose

36. Let’s review…
Light-dependent reactions
Light-independent reactions

37. What materials come into the chloroplast that are used in the light-dependent reactions?

38. What material comes into the chloroplast that is used by the Calvin Cycle?

39. What material moves out of the chloroplast from the light-dependent reactions?

40. What materials move out of the chloroplast from the Calvin Cycle?

41. What materials move from the light-dependent reactions to the Calvin Cycle?

42. What materials move from the Calvin Cycle back to the light-dependent reactions?

43. Factors affecting Photosynthesis
● Water
- shortage can slow or even stop photosynthesis
- plants living in dry areas have a waxy coating to
prevent water loss
● Temperature
- enzymes used in photosynthesis function best
between 0°C and 35°C
- high or low temps slow down or stop photosynthesis
● Intensity of light
- increasing light intensity increases the
rate of photosynthesis
- plants eventually reach their maximum

44. Factors that can affect photosynthesis
1. Amount of water 2. Temperatures 3. Light Intensity 4. Amount of CO2

45. And Now………. THE PHOTOSYNTHESIS RAP!

46. Where in the plant cell does photosynthesis take place?
Chapter 8
Cellular Energy
8.2 Formative Questions
Where in the plant cell does photosynthesis
take place?
chloroplasts
Golgi apparatus
mitochondria
vacuoles

47. STOP!
Using the cards provided, at your lab table, assemble the equation for photosynthesis with your lab partner(s).
On a piece of paper, each person should draw a diagram of a plant showing the typical inputs and outputs of the photosynthetic process with your lab partner (s).
Write the equation for photosynthesis on the paper as well.