1. PHOTOSYNTHESIS

2. Photosynthesis Anabolic (small molecules combined)
Endergonic (stores energy)
Carbon dioxide (CO2) requiring process that uses light energy (photons) and water (H2O) to produce organic macromolecules (glucose).
6CO H2O  C6H12O O2
glucose
SUN
photons

3. Where does photosynthesis take place?
Question:
Where does photosynthesis take place?

4. Plants Autotrophs – produce their own food (glucose)
Process called photosynthesis
Mainly occurs in the leaves:
a. stoma - pores
b. mesophyll cells
Mesophyll
Cell
Chloroplast
Stoma

5. Stomata (stoma)
Pores in a plant’s cuticle through which water vapor and gases (CO2 & O2) are exchanged between the plant and the atmosphere.
Guard Cell
Oxygen
(O2)
Stoma
Carbon Dioxide
(CO2)
Found on the underside of leaves

6. Mesophyll Cell of Leaf Photosynthesis occurs in these cells! Nucleus
Cell Wall
Chloroplast
Central Vacuole
Photosynthesis occurs in these cells!

7. Chloroplast Organelle where photosynthesis takes place.
Stroma
Outer Membrane
Thylakoid
Granum
Inner Membrane
Thylakoid stacks are connected together

8. During the fall, what causes the leaves to change colors?
Question:
During the fall, what causes the leaves to change colors?

9. Fall Colors
In addition to the chlorophyll pigments, there are other pigments present
During the fall, the green chlorophyll pigments are greatly reduced revealing the other pigments
Carotenoids are pigments that are either red, orange, or yellow

10. Energy All organisms need a constant source of energy to survive.
That energy source is the sun.

11. Photosynthesis
The overall process by which sunlight (solar energy) chemically converts water and carbon dioxide into chemical energy stored in simple sugars (glucose).

12. Photosynthesis Occurs in 2 Stages:
Light-dependent Reactions
Light-independent Reactions

13. Light-Dependent Reactions
They are called light-dependent because they require solar energy.
The solar energy is absorbed by chloroplasts.
After absorption 2 different energy storing molecules (ATP & NADPH) are produced.

14. Light-Dependent Reactions
The solar energy is used to split water molecules which results in the release of oxygen as a waste product.
This is an essential step in the process of photosynthesis.

15. Light-Independent (DARK) Reactions
It’s called dark (or light-independent) because solar energy is not required.
During this reaction, energy stored as ATP & NADPH is used to produce simple sugars (glucose) from carbon dioxide.
These sugars are used to store chemical energy for use by the cells at later times.

16. Light-Independent (DARK) Reactions
Glucose is used as an energy source through the process of cellular respiration OR it can be converted to organic molecules (Proteins, lipids, carbohydrates, or cellulose).

17. The Equation: 6CO2 + 6H2O  C6H12O6 + 6O2
Six carbon dioxide molecules and six water molecules are needed to produce one glucose molecule and six oxygen molecules.
Each of the reactants (CO2 & H2O) is broken down at different stages of the process.
Each of the products (O2 & C6H12O6) is formed in different stages of the process.
Solar energy is needed to break down the water molecules.

18. What do cells use for energy?
Question:
What do cells use for energy?

19. Energy for Life on Earth
Sunlight is the ULTIMATE energy for all life on Earth
Plants store energy in the chemical bonds of sugars
Chemical energy is released as ATP during cellular respiration

20. Structure of ATP ATP stands for adenosine triphosphate
It is composed of the nitrogen base ADENINE, the pentose (5C) sugar RIBOSE, and three PHOSPHATE groups
The LAST phosphate group is bonded with a HIGH ENERGY chemical bond
This bond can be BROKEN to release ENERGY for CELLS to use

21. DEPHOSPHORYLATION-Removing a Phosphate from ATP
Breaking the LAST PHOSPHATE bond from ATP, will ---
Release ENERGY for cells to use
Form ADP
Produce a FREE PHOSPHATE GROUP

22. High Energy Phosphate Bond

23. FREE PHOSPHATE can be re-attached to ADP reforming ATP
Process called Phosphorylation

24. Phosphorylation