Photosynthesis
Light Reactions and Calvin Cycle
Review
• Autotrophs make their own food by trapping light. What’s
this called? Write out the formula:
• 6CO2 + 6H2O + light energy ---> C6H12O6 + 6O2
• Animals harvest the energy through a process called what?
Write out the formula:
• C6H12O6 + 6O2 ---> 6CO2 + 6H2O + ATP
Review
• If two plants had exactly the same growing
conditions (soil, nutrients, temperature, etc),
but one had only green light and the other
had only blue light, which one would grow
better? Why? Discuss with your neighbor
after you write down with your own answer.
Objectives
1. Describe the makeup of a chloroplast
2. Understand the light reactions and Calvin
Cycle
Photosynthesis:
What’s happening inside the chloroplast
•
Chloroplast:
– Organelle where
photosynthesis takes
place
•
Two reactions taking
place:
1. Light Reactions
2. Calvin Cycle
Where Photosynthesis Happens
• Thylakoid:
– pancake structure,
membrane, light
reactions
• Granum:
– stack of thylakoids
The chloroplast
• Thylakoids have a very high surface area to volume
ratio.
• Why is this important?
Light Reactions
Inside the Thylakoid Membrane
1. Chlorophyll
captures light
energy
2. Electrons removed
from water
3. 02 (waste) escapes
through stomata
4. Chloroplasts make
energy (NADHP &
ATP)
Calvin Cycle:
A Sugar Factory
• Inputs:
– C02 from the air &
energy from light
reactions
• Does NOT use light
• Produces sugar
Review
• What are the inputs and outputs of the light
reactions?
– Inputs: H2O and light
– Outputs: O2 and ATP
• What are the inputs and outputs of the Calvin
cycle?
– Inputs: CO2 and ATP
– Outputs: glucose