Transcript Photosynthesis-I

Announcements
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Tomorrow’s recitation quiz NEJM #1
iclickers mini-quiz academic honesty
GATTACA ec Tonight 7pm C-106
Order your primers [oligos] yet?
Raise hand if you read pp185-189.
Read because not just lecture here
cytoplasm
outside cell
Based on the model of sucrose uptake shown, which of the following
treatments would increase the rate of sucrose transport into the cell.
a. Decreasing extracellular sucrose concentration.
b. Decreasing extracellular pH
c. Decreasing cytoplasmic pH
d. Adding an inhibitor that blocks the creation of ATP.
e. Adding a substance that makes the membrane more permeable to H+
Post- test
Leaves contain millions of chloroplasts.
Cell
Chloroplasts
Chloroplasts are highly structured, membrane-rich organelles.
Outer membrane
Inner membrane
Thylakoids
Granum
Stroma
Where do plants get their ‘food’...
CO2
CO2
CO2
Thin Air...
Short Experiment:
Growing radishes from seed
Biology Radish Problem
Weighed out 3 batches of radish seeds (each 1.5 g).
Experimental treatments:
» 1. Seeds not moistened (dry) placed in LIGHT
» 2. Seeds on moistened paper towels in LIGHT
» 3. Seeds on moistened paper towels in DARK
After 1 week, all plant material was dried & weighed.
TASK: Predict the (dried) biomass of the plant
material in the various treatments.
Results: Weight of
Radish Seedlings
1.46 g 1.63 g 1.20 g
How do you explain the results?
(Remember all treatments started as 1.5g).
When Light Is Absorbed, Electrons
Enter an Excited State
Time to capture photons (photosystem football)
Question for Thursday: How is this image relevant to
Digestion, Cell Biology, Respiration and PHS?
ATP powers everything
Peter Mitchell: Diffusion is the answer!
Paul Boyer: I think it actually twists!
Masasuke Yoshida “Ummm… check this out.”