Photosynthesis Aftermath

10/23

Friday: Transpiration Abstract Due
Monday (after Exam): Enzyme Abstract Due

What are we going to do with this computer simulation exercise?

1. No abstract
2. Worksheets only
3. Homework: 2 worksheets...very brief
4. Total of four worksheets: Exploring, Core1-3

What did you learn so-far in exploring the computer simulation?

Photosynthesis:

CO₂ + H₂O light
---------->
chlorophyll) CH₂O + O₂
Respiration:
CH₂O + O₂ ----------> CO₂ + H₂O + Energy (ATP)

What factors affect the rate of photosynthesis?

Light Intensity
Light Wavelength
CO2 concentration
Water and Stomata
Temperature

Light Intensity

Intensity not same as Photon Flux (PF) or Photosynthetic Photon Density (PPD)
Page 2: What was shape of curve for Rate vs Intensity?
What if we put both reactions on same graph?
Compensation point = level of factor causing photosynthesis to compensate for respiration

Wavelength

Visible spectrum:
Why is Chlorophyll Green?
Action spectrum vs Absorption Spectrum: Page 10
Why does green light work at all?
What are antenna pigments?
How does chlorophyll work?
Porphyrin ring
Magnesium ion
Phytol tail
How do electron carriers (quinones, cytochromes, cyanins) pass electrons?
Where is light reaction occurring (thylakoid or stroma?)
which reactions quit first when light was cut?(Core 1)

Carbon Dioxide

What was the shape of curve on Page 3?
Why does it plateau? limiting factors
When was the % enchancement best for added carbon dioxide (Page 4)?
Where does the oxygen go? (Core 1)
Where does carbon dioxide enter photosynthesis (thylakoid or stroma)?
which reactions quit first when CO2 was cut? (Core 1)
Why did cutting CO2 ultimately stop the light reactions? (Core 1)

Water

Through what other factor does water work? CO₂ via stomatal closure (Page 5)
What is the main use of water in a plant?
Why does it say that PS use of water is a small percentage?
How much water is in a plant cell? Could it ever be limiting to a chloroplast?
Where does the oxygen go? (Core 1)
Where does the hydrogen go?

Temperature

Electronic reactions should not be sensitive to "normal" range of temperatures
Enzymatic reactions ARE!
Which set of reactions (light, Calvin) would be temperature sensitive?
Why would temperature affect ALL of photosynthesis (INCLUDING electronic!)?
What was the optimum temperature for Photosynthesis?
What would be the best daytime temperature?
What would be the best night-time temperature?
How does freezing alter a cell?

In the Jar?

Now that you know something about Priestley's exercise, why did the mouse die more quickly in the dark with the plant?
Could a plant live in the jar all by itself both in day and night?
Page 12 What about direction of oxygen arrow?
What intensity did it take to change its direction?

Links?

What linked the light reactions and Calvin cycle? (Core 1)
When you blocked the links, what stopped first (thylakoid or stroma) reactions?

Overview:

What did you do for page 6 of Core 1?

Go back to the Course Schedule.