1. Day 1

2. What types of energy are there?
Some words you might have used:
chemical,
potential,
gravitational,
kinetic,
thermal,
mechanical…

3. Energy Energy is the ability to do work.
Name as many different types of energy as you can…
The two basic types of energy are kinetic energy and potential energy.

4. Energy Kinetic energy is the energy of motion.
Anything that is moving has kinetic energy

5. Energy
Potential energy is energy that is stored due to an object’s position or arrangement.

6. Energy
Energy can’t be created or destroyed, but it can change from one form to another

7. Visible Light
Light is a form of electromagnetic energy, which travels in waves
When white light passes through a prism the individual wavelengths are separated out.

8. Light Energy
Light is a form of energy called Electromagnetic Energy

9. Light Energy Light is the only source of energy for plants!
Plants convert light energy into chemical energy -> Photosynthesis
Recall that light is energy
Different colors of light have different wavelengths and different amounts of energy.
Red light = low energy
Blue light = high energy

10. Why are plants green?
A substance’s color is due to chemical compounds called pigments.
When light hits an object the wavelengths can be transmitted, absorbed, or
reflected.

11. Light Options When It Strikes A Leaf
Reflect – a small amount of light is reflected off of the leaf. Most leaves reflect the color green, which means that it absorbs all of the other colors or wavelengths.
Absorbed – most of the light is absorbed by plants providing the energy needed for the production of Glucose (photosynthesis)
Transmitted – some light passes through the leaf

12. Why are plants green?
Notice that chloroplasts absorb blue-violet and red-orange light very well.
The chloroplasts convert the absorbed light energy into
chemical
energy stored in
organic
molecules.

13. Chloroplast Are located within the palisade layer of the leaf
Stacks of membrane sacs called Thylakoids
Contain pigments on the surface
Pigments absorb certain wavelengths of light
A Stack of Thylakoids is called a Granum
Chloroplast
Mesophyll
5 µm
Outer
membrane
Intermembrane
space
Inner
Thylakoid
Granum
Stroma
1 µm

14. Chloroplast

15. Chloroplast Are located within the palisade layer of the leaf
One Membrane sacs called Thylakoids
Contain pigments on the surface
Pigments absorb certain wavelenghts of light
A Stack of Thylakoids is called a Granum
Chloroplast
Mesophyll
5 µm
Outer
membrane
Intermembrane
space
Inner
Thylakoid
Granum
Stroma
1 µm

16. Energy
How do cells “use” the stored chemical energy in organic molecules?
The stored chemical energy in organic molecules must first be converted to a type of energy that cells can use!
ATP – Adenosine Triphosphate

17. ATP ATP – Adenosine Triphosphate
ATP has lots of energy stored in the chemical bonds between the 3 phosphate groups.

18. ATP
When a bond is broken, energy is released. (ADP + P remains as products)
Cells can use this energy to do cellular work.

19. ATP What types of work do cells do?
Building macromolecules (chemical work)
Moving muscles (mechanical work)
Pumping solutes across a membrane (active transport)

20. ATP ATP is continuously converted to ADP as your cells do work.
ADP can be “recycled” back into ATP by adding a phosphate group (and some
energy)
We’ll learn more
about this when we
talk about Cellular
Respiration

21. PHOTOSYNTHESIS
Comes from Greek Word “photo” meaning “Light” and “syntithenai” meaning “to put together”
Photosynthesis puts together sugar molecules using water, carbon dioxide, & energy from light.

22. Happens in two phases Light-Dependent Reaction
Converts light energy into chemical energy
Light-Independent Reaction
Produces simple sugars (glucose)
General Equation
6 CO2 + 6 H2O+ light energy  C6H12O6 + 6 O2
INPUTS OUTPUTS

23. First Phase Requires Light = Light Dependent Reaction
Sun’s energy excites an electron in the chlorophyll molecule
Electron is passed to nearby protein molecules in the thylakoid membrane of the chloroplast

24. Excitation of Chlorophyll by Light
When a pigment absorbs light it absorbs energy
It goes from a ground state to an excited state, which is unstable
Excited
state
Energy of election
Heat
Photon
(fluorescence)
Chlorophyll
molecule
Ground e–
Figure A

25. Electron Transport Chain
Electron from Chlorophyll is passed from protein to protein along an electron transport chain
Electrons lose energy (energy changes form)
Finally bonded with electron carrier called NADP+ to form NADPH or ATP
Energy is stored for later use

26. Two Photosystems
Photosystem II: Clusters of pigments boost e- by absorbing light w/ wavelength of ~680 nm
Photosystem I: Clusters boost e- by absorbing light w/ wavelength of ~760 nm.
Reaction Center: Both PS have it. Energy is passed to a special Chlorophyll a molecule which boosts an e-

27. A mechanical analogy for the light reactions
Mill
makes
ATP e–
Photon
Photosystem II
Photosystem I
NADPH
Figure 10.14 

28. (INTERIOR OF THYLAKOID)
Photosystem
A photosystem
Is composed of a reaction center surrounded by a number of light-harvesting complexes
Primary election
acceptor
Photon
Thylakoid
Light-harvesting
complexes
Reaction
center
Photosystem
STROMA
Thylakoid membrane
Transfer
of energy
Special
chlorophyll a
molecules
Pigment
THYLAKOID SPACE
(INTERIOR OF THYLAKOID)
Figure 10.12 e–

29. Figure 10.5 H2O CO2 [CH2O] O2 (sugar) Light LIGHT REACTIONS CALVIN
CYCLE
Chloroplast
[CH2O]
(sugar)
NADPH
NADP 
ADP
+ P O2
Figure 10.5
ATP

30. Where did those electrons come from?
Water
Electrons from the splitting of water supply the chlorophyll molecules with the electrons they need
The left over oxygen is given off as gas

31. High Quality H2O Electrolysis: Splitting of water with light energy
Hydrogen ions (H+) from water are used to power ATP formation with the electrons
Hydrogen ions (charged particle) actually move from one side of the thylakoid membrane to the other
Chemiosmosis – Coupling the movement of Hydrogen Ions to ATP production

32. Light-Dependent
Converts light into chemical energy (ATP & NADPH are the chemical products). Oxygen is a by-product
Mill
makes
ATP e–
Photon
Photosystem II
(Water-splitting)
Photosystem I
(NADPH-producing)
NADPH
Figure 10.14 

33. Pigment Molecules that absorb specific wavelengths of light
Chlorophyll absorbs reds & blues and reflects green

34. Chlorophyll Green pigment in plants Traps sun’s energy
Sunlight energizes electron in chlorophyll

35. Electron Transport Chain
Series of Proteins embedded in a membrane that transports electrons to an electron carrier

36. ATP Adenosine Triphosphate
Stores energy in high energy bonds between phosphates
ATP, or adenosine triphosphate, is a method of energy storage in living organisms

37. NADPH
During the Light Dependent Cycle of photosynthesis, light is absorbed by the chlorophyll.
The electrons are excited, which starts them moving from one enzyme to another.
A hydrogen atom attaches itself to an NADP+ molecule, converting it to NADPH
Stores the high energy electrons for use during light-Independent reaction (Calvin Cycle)

38. What types of energy are there?
Engage: What’s Going On Inside a Cell?
What types of energy are there?
Food gives us E (energy) but NOT until we break it (down) into anthr (another) form.
Food is stored as chem E (chemical energy).
It has the potential to give us E but not until smthing (something) else is done to it…

39. Engage: What’s Going On Inside a Cell?
Get it Straight…
When we eat a food that has protein (prtn), that protein is not incorp. Immed into our muscles.
The prtn and other nut. are broken into sm. organ. mole.
Remem. from Chap 6 that sm organ. mole.’s r used to build the specific prtn & other mac. mole that r used by plant & animal cells.
So, don’t think that we eat smthg and it goes “straight to our hips” (or muscles or wherever)…

40. Exit Ticket
On a separate sheet of paper answer the following questions:
How do plants get energy and matter for growth?
How is energy transferred from one form to another?
How do plants get their energy from light sources?
What are the inputs and outputs of photosynthesis?
Why does photosynthesis only occur in the chloroplasts?