1. Vocabulary Grab a notebook page ADP ATP Autotroph Heterotroph
Photosynthesis
Chlorophyll
Thylakoid
Stroma
Light Dependent Reaction
Light Independent Reaction
Photosystem
Electron Transport Chain

2. Photosynthesis

3. Energy and Life
Nearly every activity in modern society depends on Energy…think about it.
Driving a car!
Typing a paper!
Using your IPOD!
Using your cell phone!
Living things also require ENERGY!

4. Where does that Energy come from?
Autotrophs (AKA: Producers)
Use the sunlight as their ENERGY source.
Heterotrophs (AKA: Consumers)
Obtain energy from the plants or other organisms that they consume.

5. Chemical Energy Candles burn
What does that mean?
Wax molecules store energy in the bonds between the hydrogens and carbons
Candle burns by melting wax into wick, vaporizing wax molecules, breaking them apart releasing heat and light

6. When the candle is burning, electrons move from higher energy levels to lower energy levels.
Heat and light energy are released.

7. Living things use and store energy
Plants make sugars and starches
Animals consume and then store sugars, starches and fats

8. Plants store energy as sugar or starch

9. Animals store energy as glycogen (animal starch)

10. Or as fat

11. ATP: Adenosine Triphosphate
Adenine
Ribose:5 carbon sugar
3 phosphate groups

12. Storing Energy
ADP (adenosine diphosphate) is a compound that looks like ATP except it is lacking a __________ group.
This one difference is the key to the way in which living things store & use energy.
Phosphate

13. Storing Energy (cont.)
When a cell has energy available, it can store small amounts of it by adding a phosphate group to ADP, producing ATP.
Think of ATP as a fully charged battery and ADP as only a partially charged battery.
Now that we have Energy stored…how do we release it?....

14. Releasing Energy
Energy that is stored in ATP is released by breaking the chemical bond between the second and third phosphates.

15. What the energy in ATP can do
Active transport
Protein synthesis
Muscle contraction

16. What the energy in ATP can do
Synthesis of nucleic acids
Move organelles throughout the cell
Responds to chemical signals of cell
Fireflies! (bioluminescence)

17. Question????? Do you think cells have an abundant amount of ATP? Why?
Answer: Most cells have only a small amount of ATP, enough to last them for a few seconds of activity.
Why?
Answer: ATP is great for transferring Energy, not for storing Energy.

18. ATP Wrap-UP
Long term storage is done by other molecules, such as glucose, glycogen, starch
ATP can be regenerated by the cell over and over again
ADP + Energy + P → ATP
Required energy comes from food molecules

19. 8-3: The Reactions of Photosynthesis
Where does photosynthesis take place?
Chloroplasts!

20. Parts of the chloroplast
Thylakoids-Proteins in the thylakoid membrane organize chlorophyll and other pigments into clusters known as photosystems.
Granum – Stack of thylakoids
Stroma – The fluid portion of the chloroplasts, outside the thylakoids

21. 8-2:Overview of Photosynthesis
Jan Van Helmont’s Experiment
Plants gain mass from water
Joseph Priestley
Plants produce oxygen
Jan Ingenhousz
Light is necessary

22. 8-2:Overview of Photosynthesis
Photosynthesis converts light energy into the chemical energy of sugar and other organic compounds.
Light energy drives the reactions
O2- byproduct and is released into atmosphere

24. The Photosynthetic Equation

25. Light and Pigments Pigments: light absorbing molecules
Chlorophyll absorbs blue-violet and red light
When a pigment absorbs light, it absorbs the energy from that light
Energy excites electrons

26. Light-Dependent Reactions
The light-dependent reactions produce oxygen gas and convert ADP and NADP+ into ATP and NADPH.
Occur in the thylakoid

27. Calvin Cycle (light-independent)
The Calvin Cycle uses ATP and NADPH from the light-dependent reactions to produce high-energy sugars.
It takes carbon dioxide from the atmosphere and converts it into high-energy sugars that can be used to meet the plant’s energy needs and to build more complex molecules.

28. What does all of that mean?
The two sets of photosynthetic reactions work together…
The light-dependent reactions trap the energy of sunlight in chemical form
The light-independent (Calvin cycle) uses that chemical energy to produce stable, high-energy sugars from carbon dioxide and water.

31. Factors Affecting Photosynthesis
Shortage of water can slow down or stop photosynthesis
Plants have adaptations to reduce water loss: waxy coating on plants in dry areas.
Temperature
Plants have enzymes that work best from degrees F. Temperatures above or below can damage these enzymes which can slow down or stop photosynthesis.

32. Factors Affecting Photosynthesis

33. Factors Affecting Photosynthesis
Intensity of light
Increasing light intensity increases the rate of photosynthesis. (It will reach a max level)

34. Factors Affecting Photosynthesis