1. Photosynthesis

2. Energy Visible light Cellular Respiration Photosynthesis
C6H12O6 + 6O CO2 + 6H2O
6CO2 + 6H2O C6H12O6 + 6O2

3. Photosynthesis 6CO2 + 6H2O C6H12O6 + 6O2
Photosynthesis uses the energy of sunlight to convert water and carbon dioxide into high-energy sugars and oxygen
6CO2 + 6H2O C6H12O6 + 6O2
carbon dioxide + water sugars + oxygen
light

5. How plants capture sunlight
Use sunlight
Form of energy – Radiation
Travels in waves
Distance between crest of one wave and crest of another wave is the wavelength
Acts likes it is made up of particles

6. Short wavelengths –high energy Long wavelengths- low energy
Photon
massless particle traveling in a wave like pattern and moving at the speed of light
Vary in energy levels
Short wavelengths –high energy
Long wavelengths- low energy

7. Electromagnetic Spectrum

8. Electromagnetic Spectrum
Gamma, Xrays: do not reach the earth - are deflected
Ultraviolet (UV): most are absorbed by the ozone layer. (sunburn and skin cancer)
Visible light (ROYGBIV): violet= highest energy and red = lowest energy

9. Electromagnetic Spectrum
Infared light ( heat):
Most light is absorbed by CO2 in atmosphere. It acts like a “blanket” which keeps the earth warm after the sun goes down.
Greenhouse effect- buildup of CO2 in atmosphere
Radio waves: the lowest energy photons; these tend to bounce

10. Pigments Substance that absorbs light is called a pigment
Light is either absorbed, reflected or passed through
Principle pigment is chlorophyll
Chlorophyll a and b=absorb red and violet/blue light and reflect green

11. Absorption Spectrum
Graphs which plots absorbance of light against different wavelengths of light

12. Photosynthesis
The process by which plants use light energy to make food from carbon dioxide (CO2) and water
The most important chemical process of Earth- supplies food for almost all organisms

13. Photosynthesis Overall reaction occurs in the chloroplasts
6CO2 + 6H2O C6H12O6 + 6O2
carbon dioxide + water sugars + oxygen

14. Photosynthesis
Completed through two main group of reactions: Light and dark reactions

15. Organisms that photosynthesize
Autotrophs
Contain chloroplasts that produce glucose= photosynthetic autotrophs- plants and some bacteria and protists.
Also called producers- they produce the worlds food supply

16. Parts of a plant that photosynthesize
All green parts have chloroplasts- photosynthesis occurs
Leaves are major sites
Stomata-”gates” on the underside of the leaf that allow the passage of gas into and out of the leaf.
Mesophyll- the green cells in the interior of the leaf, most often on the upper side- concentrated with chloroplasts
Chloroplasts contain chlorophyll and are specific sites of photosynthesis

17. Structure of a Chloroplast
Inner and outer membrane separated by an intermembrane space.
Stroma- thick fluid inside the inner membrane – where sugars are made
Thylakoids – disk-like membranous sacs, suspended in the stroma
Contain fluid within membranes
Chlorophyll molecules built in the membrane
Grana- stack of thylakoid membranes

18. How it works
Sunlight enters chloroplast

19. 2. Light is absorbed by the chlorophyll – green is reflected
This occurs in photosystem II
Used to break up water molecules into energized electrons, hydrogen ions, and oxygen

21. 3. ATP molecules are formed using light energy
ADP- adenosine diphosphate
Stored energy
Di – two
ATP – adenosine tri phosphate
Tri - three
Bond breaks and releases energy

22. Light Dependent Reactions
4. Light energy is used to break bonds in water molecules
produce ATP, NADPH and oxygen
These reactions take place in thylakoid membranes

23. Light dependent Reactions
Photosystem II- Light absorbed by photosystem II is used to break up water molecules into energized electrons, hydrogen ions, and oxygen
Electron Transport Chain – High energy electrons from photosystems II move through the ETC to photosystem I

25. Light Dependent Reactions
Photosystem I – Electrons released by photosystem II are energized again in photosystem I.

26. Light Dependent 5. Hydrogen are fused to NADP molecules creating NADPH
Enzymes in the membrane use the electrons to form NADPH. NADPH is used to make sugar in the Calvin Cycle.
6. Oxygen is expelled as waste
7. NADPH and ATP are moved from granum to stroma

27. CALVIN CYCLE
Plants use the energy that ATP and NADPH contain to build high energy compounds that can be stored for a long time.
Doesn’t need light, also called light independent reactions
8. In the stroma-
NADPH & ATP are used to join CO2 molecules and hydrogen into sugar
9. Sugar is stored or used by cell

28. Calvin cycle
Uses six molecules of CO2 to produce a single 6-carbon sugar molecule
removes CO2 and turns it into energy rich carbohydrates
Plants use sugars for energy and build more complex molecules (cellulose) for growth and development
Other organisms eat plants to gain the energy they need

29. 10. NADP & ADP are moved back into the granum and the process starts again