1. Photosynthesis & Respiration
Chapters 11 & 12

3. Properties of Photosynthesis
CO2 +
H20
CH0 +
H20 O2

4. Factors Affecting the Rate
Light Quality
Light Intensity
Light duration
Carbon Dioxide
Temperature
Water Availability
Plant Development

5. Photophosphorylation
12 H2O O H e-
Overall Light reaction equation

6. Photophosphorylation
12 NADP H2O NADPH H O
Oxidized form
Reduced form
NICOTINAMIDE ADENINE DI NUCLEOTIDE PHOSPHATE

7. Stage 1 – Light reaction Photophosphorylation
The light reaction: have the chlorophyll use light energy to split water to release
an e- to start the process. - To get an NADPH (an electron carrier)
Light Energy
H2O +ADP + Pi + NADP  ATP + NADPH Chlorophyll H+ + ½ O2
NICOTINAMIDE ADENINE DI NUCLEOTIDE PHOSPHATE
This sequence represents the transfer of four electrons from water to two molecules of NADPH also during this step the conversion of ADP to ATP

8. Overview of Photosynthesis and Respiration

9. Photophosphorylation
ADP + P ATP
Adenosine Triphosphate

10. Photophosphorylation
12 NADP e H+ + 12ADP + 12P
12ATP NADPH
Overall energy equation

11. Review 24e- 12 H2O 6O2 + 24 H+ + 1.____ ADP + P 3. ___ ATP
12 2._____ +12 H2O NADPH H O
NADP+
ADP + P
3. ___ ATP
12 NADP e H+ 12ADP + 12P
4. _______________
12ATP NADPH

12. Light-Dependent and Light Independent Reactions
Photosynthesis
Light-Dependent and Light Independent Reactions

20. Stage 2 – Dark reaction
Using the energy of energy carriers ATP and NADPH, CO2 can be coaxed into
carbohydrates - this step is sometimes referred to as the dark reaction of
photosynthesis.

21. Carbon Dioxide – CO2
Water – H2O
Light Energy
Oxygen – O2
Glucose C6H12O6
Calvin
Cycle
Light
Reactions

24. What Happens to the Glucose?
Glycolysis, the anaerobic breakdown of glucose.
enzymes
Glucose + 2ATP  2 pyruvic acid + 2 ATP + 2 NADH + 12H2O
*occurs in the cytoplasm of the plant cell
The 2NADH release 6 ATPs

25. What Happens to the Pyruvic Acids?
The Pyruvic acids Go through Citric Acid Cycle or Krebs Cycle
mitocondria pyruvic acid 8 NADH + 2 FADH2 + 2 ATPs and 6CO2
Then in the mitochondria the 8 NADH + 2 FADH2 is converted to:
one NADH releases 3 ATP for a total of 24 ATP
one FADH2 releases 2 ATP for a total of 4 ATP (don’t forget those from glycolysis) 38
Total ATP released per glucose molecule?

27. The Dark Reaction can take one of three different paths.

28. Path 1
C3 Plant –called this because the first carbon compound formed has three carbon atoms
the most common type : commonly referred to as CALVIN CYCLE
6CO NADPH2 + 18ATP  C6H NADP ADP + 18Pi + 6H2O

29. Path 2
C4 Plant – they’re first carbon compound has four carbon atoms. They can use CO2 more efficiently and thus grow faster. Corn, sugar cane, Crabgrass, Johnson grass, Bermuda grass, pigweed, purslane.

30. Path 3
CAM – Crassulacean Acid Metabolism allows the plant to store CO2 the plants in the
cactus, orchid and bromeliad families.

32. Comparison Requires CO2 and H20 O2 and C6H12O6
Photosynthesis Respiration
Requires CO2 and H O2 and C6H12O6
Produces O2 and C6H12O CO2 and H20
Energy Stores energy Releases energy
Occurs in the Light only Light and Dark presence of
Only in Chlorophyll All living cells containing cells respire

33. Photosynthesis Respiration
Source of electrons Hydrogen Hydrogen from H from C6H12O6
Use of ATP & ATP and NADPH ATP and NADPH used for sugar NADPH plant for Synthesis functions (stored) (immediate use)

34. Absorption Translocation & Assimilation
Of all the water taken in by the plant only about 1-5% of the water is utilized for photosynthesis. Transpiration is the loss of water from the plant primarily through the stomates in the leaf.
Absorption
Will take place in the roots through the root hair and around the root hair
Water is taken in and transported to other parts through the xylem.

35. Minerals are dissolved in solution and. are transported into the xylem
Minerals are dissolved in solution and are transported into the xylem tissues this process is called , active transport. This process requires energy.

36. Water movement
Accomplished by transpiration, adhesion, cohesion and tension.
Adhesion is the attraction of water various materials. Water wants to surround things
Cohesion is the attraction water has towards itself
Tension is a pulling force exerted onto the xylem.
So water is lost through transpiration from the leaf and the loss pulls the water from the adjacent cell and so on and so on.