1. The Energy & Matter: Shaping and Organizing Living Systems
Photosynthesis
The Energy & Matter: Shaping and Organizing Living Systems

2. CA Biology Standards
Students know usable energy is captured from sunlight by chloroplasts and is stored through the synthesis of sugar from carbon dioxide.
NGSS-HS-LS1-5. Use a model to illustrate how photosynthesis transforms light energy into stored chemical energy.

3. Objectives
The conservation & transformation of energy & matter affect all levels of life.
Organisms break the chemical bonds of food molecules, forming different molecules with lower amounts of energy. As a result, energy is released.
Many organisms have specialized cells, tissues, organs, and organ systems to obtain and construct the molecules necessary for life.
Photosynthesis transforms light energy into chemical energy.
Energy flows through ecosystems and matter cycles.
The flow of energy and the cycling of matter can help inform current debates about the use of traditional and alternative biofuel

4. Biofuel

5. Biofuel Video

6. What are the various forms of energy that exist?
Write your answer in your journal.
Energy is neither created nor destroyed.
Energy is transferred from one form to another.

7. Forms of energy Potential energy-stored energy
Kinetic Energy-energy of movement of objects

8. Transfer of Energy
Autotrophs (producers) are organisms that create their own food by photosynthesis (light energy)

10. Structure of a Leaf
Specialized organelle for photosynthesis is the chloroplast.
Two main compartments:
1. Thylakoid
2. Stroma

11. Visible Light Why do plants appear green?
Chlorophyll absorbs red & blue spectra and reflects green wavelengths

12. Pigments can be classified as which kind of organic compound?
Lipids
Chlorophyll

13. ATP: The Cell’s Currency
Adenosine Triphosphate (ATP)
Energy from food is converted into high energy bonds in ATP
ADP + P + energy  ATP

14. ADP ATP Adenosine diphosphate (ADP) + Phosphate
Energy
Energy
Adenosine diphosphate (ADP) + Phosphate
Adenosine triphosphate (ATP)
Partially
charged
battery
Fully
charged
battery

15. Overview of Photosynthesis
6 CO2 + 6 H2O + electron  C6H12O6 + 6 O2
Reactants Products
Basis of most of the earth’s food chains
Produces and maintains all of the earth’s atmospheric oxygen
Most oxygen produced in the oceans

16. Photosynthetic Pigments
Mostly chlorophyll a and chlorophyll b
Accessory pigments:
Carotenoids
Anthocyanins
Each pigment absorbs a particular wavelength of light in the visible spectrum

17. At which wavelength does chlorophyll absorb the most light? Least?
Pigment Absorption

18. Step I: Light Reactions
Occurs in thylakoid membrane of chloroplast
H2O is taken into plant by roots
Formation of O2 from H2O
H2O is oxidized by the splitting of water (photolysis)
Light energy is converted into chemical bond energy
ATP, NADPH, H+, and O2 are generated
12 H2O + Energy  6 O H e-

19. Overview of the Light Reactions
Think of the light reaction, as a process by which organisms "capture and store" radiant energy as they produce oxygen gas.
This energy is stored in the form of chemical bonds of compounds such as NADPH and ATP.

21. Step II: Light Independent (Calvin Cycle)
Occurs in the stroma (No light necessary)
The energy from NADPH and ATP is used for carbon fixation (converting inorganic carbon to organic compounds)
Formation of glucose from CO2
6 CO H e > C6H12O H2O
The chemical bonds present in glucose also contain a considerable amount of stored (potential) energy.

22. Guard Cells-open or close based on turgor pressure

23. Overview of the Dark Reactions
Carbon dioxide is broken and “fixed” into glucose or fructose molecules in the CALVIN CYCLE!!!!
Glucose subunits can make cellulose or other polysaccharides, such as fruit sugars.

24. Video Clip-Teacher Domain

25. O2 Light ATP CO2 ADP + P NADPH Calvin Cycle NADP+ Sugars Chloroplast
Dependent
Reactions
NADPH
Calvin
Cycle
NADP+

26. Factors Affecting Photosynthesis
Water
shortage of water can slow/stop photosynthesis.
Desert plants have waxy coating on leaves (reduce water loss)
Temperature
Photosynthesis depends on enzymes which function best between 0°C and 35°C.
Temperatures above or below can damage enzymes, slowing down enzyme activity.
Intensity of light

27. Quiz Complete the sentences below:
Energy is neither _______ nor __________. It is merely __________into another form.
When bonds break, energy is _________. When bonds form, energy is _________.

28. Select the best answer choice for the following statements.
3. The specialized organelle in which molecules of glucose are formed is the
Mitochondria
Nucleus
Cell membrane
Chloroplast
Chlorophyll

29. 4. During photosynthesis, light is transformed to
Mechanical energy
Chemical energy
Heat energy
Electrical energy

30. 5. Energy flows through ecosystems beginning with
Producers
Heterotrophs
Decomposers
Carnivores
Sunlight

31. What are some of the advantages of using plants to generate biofuel?
What are some disadvantages of using plants to generate biofuel?

32. Photosynthesis Recipe
Complete the photosynthesis recipe card for homework.