1. 8.2 Photosynthesis

2. Overview Happens in plants when they take in water and CO2
Photosynthesis occurs in 2 phases.
Phase one- light reactions
Phase two – the Calvin cycle

3. Phase one: Light Reactions
This process starts with light being captured by chloroplasts.
Chloroplasts are found mainly in the cells of leaves.
Q: why do you think chloroplasts are found mainly in leaves?
The light dependent reactions take place in the thylakoids.
Phase two takes place in the stroma.

5. Phase one: Light Reactions- 1st period skip
Pigments- light-absorbing molecules that are found in the thylakoid.
Different pigments absorb different wavelengths of light.
The major light-absorbing pigments in plants are chlorophylls. There are two of these; chlorophyll a and b.
In general, chlorophylls absorb most strongly in the violet- blue region of the light spectrum, and reflect in the green region.

6. Phase one: Light Reactions
The structure of the thylakoid membrane is the key to efficient energy transfer during electron transport and chemiosis.
What is produced during electron transport?
Chemiosis is a process that helps ATP be produced.

7. Phase two: The Calvin Cycle
The calvin cycle is the process of converting large amounts of energy (ATP, NADPH) to a stable, storable form of energy, called glucose.
What is produced from the calvin cycle?

8. Alternative Pathways
Not all plants live in an environment that has a lot of water and therefore not all plants can carry out photosynthesis as easily as others.
C4 plants- these plants are different because they have carbon in groups of 4 during the calvin cycle instead of groups of 3. They also keep the stomata on the surface of their leaves closed during the day in order to decrease water loss.

9. Alternative Pathways
Not all plants live in an environment that has a lot of water and therefore not all plants can carry out photosynthesis as easily as others.
CAM plants- These plants (cacti, pineapples, orchids) only allow CO2 to enter the leaves at night when the atmosphere is cooler and more humid.
At night, carbon is fixed into organic compounds and it is released into the calvin cycle during the day.

10. Key points- write this whole slide including formula
Phase 1- light is absorbed and converted to ATP for energy to phase II, oxygen is also released.
Phase II- CO2 is changed to glucose through the calvin cycle.
Through two phases (light reactions and calvin cycle) plants are capable of taking our CO2 along with water, and converting it into glucose and oxygen for us to breath.