Post on 24-Dec-2015
Concept 2: Analyzing the Processes of Photosynthesis
Refer to pg 83-92 in Holtzclaw, Ch 10 in Campbell and media resources
Refer to pg 297-299 in Holtzclaw, Lab Inv 5 in Lab Manual
Try This!
Where does the biomass of a tree primarily come from?
A. Oxygen
B. Water
C. Carbon dioxide
D. Light
E. Fertilizer
Try This!
Where does the biomass of a tree primarily come from?
A. Oxygen
B. Water
C. Carbon dioxide
D. Light
E. Fertilizer
CO2
A building block for organic molecules!
Try This!
An acorn grows into an oak tree. The main source of the additional mass present in the oak tree is:
a. Water from the soil
b. Minerals from the soil
c. CO2 from the air
Try This!
An acorn grows into an oak tree. The main source of the additional mass present in the oak tree is:
a. Water from the soil
b. Minerals from the soil
c. CO2 from the air
CO2
A building block for organic molecules!
Photosynthesis(Chapter 10)
You must know:
The summary equation of photosynthesis including the source and fate of reactants and products
How the leaf and chloroplast anatomy relates to photosynthesis
How photosystems convert solar energy to chemical energy
How linear electron flow in the light reactions results in the formation of ATP, NADPH, and O2
How chemiosmosis generates ATP in the light reactions
How the Calvin cycle uses the energy molecules of the light reactions to produce G3P
Photosynthesis – The Basics
CO2 + H2O → C6H12O6 + O2
1)Light Reactions “photo”
2)Calvin Cycle “synthesis”
The Light Reactions
Light energy excites electrons in chlorophyll
Removal of electrons from H2O
Formation of O2
Electron Transport Chain Reduction of NADP+ to NADPH
Proton Motive Force
ATP Synthase to produce ATP
H+! Proton Motive
Force
H+! Proton Motive
Force
H+! Proton Motive
Force
Try This
Unlike in cellular respiration, the proton motive force generated by the light reactions in photosynthesis happens in three ways… Can you remember the three ways?1. Electron transport chain powering the active transport
of H+ into the thylakoid space
2. H+ produced in the thylakoid space from the splitting and oxidation of water
3. Removal of H+ from stroma during the reduction of NADP
+ to NADPH
The Light Reactions
Light energy excites electrons in chlorophyll
Removal of electrons from H2O
Formation of O2 (leaves stomata as a gas)
Electron Transport Chain Reduction of NADP+ to NADPH
Proton Motive Force
ATP Synthase to produce ATP
The Light Reactions
The whole point was to transfer light energy to chemical energy in the form of: electrons in NADPH ATP
Why? To power carbon fixation in the
Calvin Cycle…
The Calvin Cycle
CO2 enters as a gas through the stomata (openings) of the leaves
Through the power of NADPH and ATP, CO2 gets converted into an organic compound: a 3-carbon sugar called glyceraldehyde-3-phosphate (G3P) Can be converted to glucose, sucrose, starch, etc…
Carbon Fixation!
The whole point…
Try This!
Which experiment will produce 18O2?
A. Exp 1
B. Exp 2
C. Both!
D. Neither!
Try This!
Which experiment will produce 18O2?
A. Exp 1
B. Exp 2
C. Both!
D. Neither!
Next Class…
Adaptations to hot, arid climates… CAM plants and C4 plants
Now…
Practice Try #12 – 15, 17-19, 21-22 p. 91-92 Go over Comparison Charts Try animation activities (Campbell Online)
Read about CAM plants and C4 plants P. 88-89 Holtzclaw P. 200-202 Campbell Activity: Photosynthesis in Dry Climates (Campbell Online)