1. Starter: Notes and ws 77 Photosynthesis notes Photosynthesis notes 78
10/28-29/13
10/28-29/13
Starter:
What is photosynthesis?
10/29- What structure in the plant contains chlorophyll?
Application/Connection/Exit:
Notes and ws
Practice: Questions:
1What is photosynthesis?
2. What organisms conduct photosynthesis?
3. If plants get their energy/food from photosynthesis, how do animals get their energy/food

2. 1 Starter 2. Cards 3. Exit
October 24, 2013 AGENDA B.9 B. I will Compare the reactants and products of photosynthesis and cellular respiration in terms of energy and matter while completing notes.

3. Table of Contents Date Lecture/ Activity/ Lab Page
10/15 Cell Transport and Homeostasis Term Notes
10/16 Osmosis in Cells Lab
10/ Observing Osmosis in Elodea
10/ Cell Analogies Poster
10/ Cell Transport Cards
10/ Experimental Design

4. PHOTOSYNTHESIS

5. It’s all about ENERGY!
Energy flow through the ecosystem allows life to exist.
All organisms require energy to live.
Some organisms produce their own food as energy, such as autotrophs (producers)
Some convert sunlight into food by the process of photosynthesis. Ex: plants, algae
Some convert chemicals into food by the process of chemosynthesis. Ex: sulfur bacteria in deep sea.
Energy is stored in food as chemical energy.

6. ATP is a bundle of energy!
ATP= adenosine triphosphate
ADP= adenosine diphosphate
ADP and single phosphate groups are available in cells to store up extra energy.
When energy is released from food, it can be stored in the bonds that bind the phosphate group to the ADP molecule.
That stored energy is later released when the bond breaks between the ADP and P.
ADP + P  ATP (stored energy)
ATP  ADP + P (energy released)

7. Energy is stored in ATP
Stored energy (created by cellular respiration)
Released energy (used for cellular activities)

8. What is the ultimate source of ALL energy?
The sun. Ask the students where they have heard this in previous units?

9. How does energy get from the sun into the foods we eat?
Accept all answers.
Tell the students this is the major concept we want them to learn today.

10. The sun sends downs little packets of light energy called: PHOTONS
Photons group together in waves, each “wave” having a different length and color
Photons
Wavelengths
Photons are packets of energy. This is one property of light energy.
This slide should be used to help the students understand the concept, but they need not be tested on this.

11. Why do we see colors???
Plants appear GREEN because they reflect this color
of light
(and they absorb red, orange, and violet)
Pigments absorb wavelengths of light. The wavelengths not absorbed are reflected. The colors we see are the reflected wavelengths.
The visible spectrum are the wavelengths that can be reflected.
Plants absorb most of the energy from the wavelengths at the 2 ends of the spectrum.
What colors of light would a plant with purple leaves absorb? all colors except violet.
Compounds that absorb and reflect wavelengths of light
are called pigments.

12. What colors are being absorbed and what colors are being reflected?
The green plant reflects the color green and absorbs all other wavelengths.
The purple flower reflects the color purple and absorbs all other wavelengths.
The white flower reflects all colors and absorbs no wavelengths.
The orange flower reflects the color orange and absorbs all other wavelengths.
The red rose reflects the color red and absorbs all other wavelengths.
Photos courtesy of flowerpictures.net and picturesof.net
Photos courtesy of flowerpictures.net and picturesof.net

13. Why do we see colors???
What do we call the compounds that absorb and reflect wavelengths of light?
pigments
Which pigment reflects the green wavelengths thereby making plants appear green?
chlorophyll
Where would we find chlorophyll?
chloroplasts
Pigments
Chlorophyll
Chloroplast

14. Chloroplast Structure
Disks called THYLAKOIDS contain the pigment CHLOROPHYLL.
FYI: A stack of thylakoids is called a grana.
The liquid portion of a chloroplast is the STROMA.

15. Where do we find chloroplasts?
Ask this question. Lead the answer to “in the cells of green plants”.

16. Chloroplasts containing chlorophyll
(Chloroplasts are found in cells of leaves and other green parts of plants.)
stomata
Chloroplasts containing chlorophyll
The leaf contains 2 important structures for photosynthesis.
The chloroplast contain the pigments (chlorophyll) necessary for photosynthesis.
The stoma are the small pores on the underside of the leaf where gas exchange occurs.

17. Review What is the ultimate source of all energy?
In what form does light energy come to the earth?
What compounds absorb wavelengths?
How do we see colors?
Where in a leaf do we find pigments?
Ask these questions one at a time as review. Click to get to the next question
1. The sun
Wavelengths
Pigments
The wavelengths not absorbed by pigments are reflected as color
In the chloroplast

18. What process captures the light energy and uses it to make food?
See if the students know the answer.
Ask what they know about the process.

19. Photosynthesis What is photosynthesis?
Photosynthesis is the process by which: Plants (producers)
light
TAKE IN
AND USING
MAKE
water
oxygen
Photosynthesis is the process by which plants (producers) take in water and carbon dioxide and using light energy and chlorophyll make oxygen and glucose
PLANTS
(producers)
carbon dioxide
glucose
chlorophyll

20. Photosynthesis 6CO2 + 6H2O 6O2 + C6H12O6 light chlorophyll
The equation shows that light and chlorophyll are needed for the reaction, but are not part of the reaction itself.

21. Where does photosynthesis occur?
Inside of chloroplasts which are located in cells of the green parts of plants

22. Photosynthesis Light reactions
Dark reactions/ light independent reactions (aka Calvin cycle)
There are two main steps to photosynthesis: the light and the dark reactions. The light reaction occurs in the grana and must have light to occur. The dark reaction was discovered by Melvin Calvin. The dark reaction occurs in the stroma. Contrary to its name, it can occur in the dark and the light.

23.  Photosynthesis Light Reactions (the “photo” part of photosynthesis)
Occur in the grana (thylakoids)
Can only occur in the presence of light
Convert solar energy to chemical energy
light 
LIGHT REACTION
Dark Reaction
Light Reaction
Dark Reaction
There are two main steps to photosynthesis: the light and the dark reactions. The light reaction occurs in the grana and must have light to occur. The dark reaction was discovered by Melvin Calvin. The dark reaction occurs in the stroma. Contrary to its name, it can occur in the dark and the light.
grana
(chlorophyll)

24. Light Reactions Step 1- Absorption of Light Energy
Pigments (light absorbing substances) in autotrophs collect sunlight that is used in photosynthesis.
Chlorophyll is stored in chloroplasts in cells.
Clusters of chlorophyll are embedded in the membranes of disk-shaped structures called thylakoids. This is where photosynthesis occurs.

25. Light Reactions Step 1- Absorption of Light Energy
Light strikes the thylakoid, causing electrons to be excited with extra energy.
The excited electrons then leave chlorophyll to jump to other molecules in the thylakoid.
The electrons that left the chlorophyll must be replaced, so they are borrowed from water molecules.
Water molecules are split, sending the electrons from the H to the chlorophyll, and giving off oxygen gas. H+ atoms are also left over.
Summation: sunlight in, energy (excited electrons) gained, oxygen gas released.

26. Light Reactions H2O O H2 (2) water is split by the light energy ENERGY
(1) light energy reacts with the chlorophyll
(2) water is split by the light energy
H2O O H2
Sunlight energy is trapped in the chlorophyll. That energy is used to split water into hydrogen and oxygen. The oxygen leaves the plant through the stoma. You can refer back to the diagram of the leaf.
(3) O2 is given off while H is kept for the dark reactions

27. Light Reactions Step 2- Conversion of Light Energy
The excited electrons leave the chlorophyll and are passed to other molecules down a series of molecules in the thylakoid membrane by a process called the ELECTRON TRANSPORT CHAIN.
Some of the energy of the electrons is used to pump H+ atoms through the thylakoid, which is then used to make ATP, stored energy.
Another ELECTRON TRANSPORT CHAIN is used to make NADPH, which is also a form of stored energy that is used to make bonds in Step 3.

29.  Photosynthesis Dark Reactions (aka Calvin Cycle)-
the “synthesis” part of photosynthesis
Occur in the stroma
Can occur in the presence of light or dark 
Light Reaction
DARK REACTION
Light Reaction
Dark Reaction
There are two main steps to photosynthesis: the light and the dark reactions. The light reaction occurs in the grana and must have light to occur. The dark reaction was discovered by Melvin Calvin. The dark reaction occurs in the stroma. Contrary to its name, it can occur in the dark and the light.
stroma
(liquid)

30. Dark Reactions Step 3- Storage of Energy
Step 3 is called the “dark reactions” , or “light-independent reactions” because sunlight is not needed.
In Step 3, the ATP and NADPH made from the earlier stages are used to make organic compounds, or the “food” (glucose)

31. Dark Reactions Step 3- Storage of Energy
The CALVIN CYCLE takes place in Step 3.
CALVIN CYCLE summary:
CO2 is added to 5-carbon compound. The process of transferring carbon dioxide to organic compounds is called CARBON DIOXIDE FIXATION.
The new 6-carbon compound splits into 2 3-carbon compounds.
Phosphate groups from ATP and electrons from NADPH are added to the 3-carbon compounds to make them 3-carbon sugars.
One of the sugars is then made into carbohydrates, and the other is recycled to make the Calvin Cycle run again.

32. Overview of the Calvin Cycle
CO2 enters the cycle and leaves as sugar.
The cycle spends the energy of ATP and NADPH to make the sugar.

33. Dark Reactions (light independent)
AKA: CALVIN CYCLE
(1) CO2 enters the chloroplast
(2) the H left from the light reactions combine with the incoming CO2
(3) Glucose is the eventual product
C6H12O6 H +
CO2
The hydrogen from the light reactions combine with carbon dioxide to form glucose.
Carbon dioxide enters the plant through the stoma.
Plants like potatoes and lettuce store sugars as complex carbohydrates such as starch and cellulose.

34. Photosynthesis Light reactions
Dark reactions/ light independent reactions (aka Calvin cycle)
There are two main steps to photosynthesis: the light and the dark reactions. The light reaction occurs in the grana and must have light to occur. The dark reaction was discovered by Melvin Calvin. The dark reaction occurs in the stroma. Contrary to its name, it can occur in the dark and the light.

35. Factors affecting photosynthesis
Intensity of light
high light, high rate
Carbon dioxide concentration
high CO2, high rate
Temperature
A certain range works best, too hot or too cold affects the work of enzymes

36. Who was Calvin anyway?
A member of the faculty at UC Berkeley since 1937, Melvin Calvin received the 1961 Nobel prize in chemistry for identifying the path of carbon in photosynthesis.
The cycle of reactions in the dark phase of photosynthesis was named after him for his work in identifying the processes taking place.

37. Photosynthesis Review
Light reactions: H2O split into H2 + O
Dark reactions: H + CO2 = C6H12O6 O2
Light Reaction
Dark Reaction
Photosynthesis Review
Light reactions: H2O split into H2 + O
Dark reactions: H + CO2 = C6H12O6
H2O
C6H12O6
chlorophyll
CO2

38. Photosynthesis Review
What goes in? (the reactants)
What comes out? (the products)
6CO2 + 6H2O O2 + C6H12O6
light
chlorophyll
H2O
Light Reaction
Dark Reaction
CO2
C6H12O6 O2
chlorophyll
The equation shows that light and chlorophyll are needed for the reaction, but are not part of the reaction itself.

39. Photosynthesis Formula
How would this be written as a chemical equation?
What goes in? (the reactants)
What comes out? (the products)
6 H2O
6 CO2
C6H12O6
6 O2
H2O
Light Reaction
Dark Reaction
CO2
C6H12O6 O2
chlorophyll