1. Photosynthesis

2. Light Absorption Sun gives off visible (white) light
How do we know this?
Sun gives off visible (white) light
White light is actually a mixture of ROY G BIV
Red, Orange, Yellow, Green, Blue, Indigo, Violet

3. Prism
White light

4. Moisture in the air can act like a prism and create a RAINBOW

5. Light Absorption Sun gives off visible (white) light
White light is actually a mixture of ROY G BIV
Red, Orange, Yellow, Green, Blue, Indigo, Violet
These colors are either reflected or absorbed by objects
We see reflected light
Green leaves = reflect green light

6. Example Which color(s) reflects? Yellow Which color(s) absorb?
All the others
I see yellow bananas.
Objects have pigments that absorb certain wavelengths of light and reflect others

7. Which color(s) reflects?
Blue
Which color(s) absorb?
All the others
I see a blue balloon.

8. Which color(s) reflects?
All
Which color(s) absorb?
None
I see white snow.

9. I see a black car (although I’m really seeing nothing).
Which color(s) reflects?
None
Which color(s) absorb?
All
I see a black car (although I’m really seeing nothing).

10. The Full Spectrum of Energy from the Sun
Our eyes can only sense this small area called “visible light”

11. Light & Photosynthesis
Most plants have green leaves, which means they:
Reflect green light (CHLOROPHYLL IS THE PIGMENT)
Absorb other colors
Energy in red and blue light most stimulates photosynthesis

12. Photosynthesis O2
CO2
reactants
products
Defined: process that converts solar energy into glucose
Who: Autotrophs (Plants, algae, some bacteria & protists)
What: Endothermic chemical reaction
Requires energy & MORE energy absorbed & CO2 & H2O
End Result:
Sugar (glucose) stored in plant
Oxygen as a waste product

13. PHOTSYNTHESIS Occurs in 2 stages 1. light dependent reactions
2. light independent reactions
Calvin Cycle

14. Stage 1: Light Dependent (Light Reactions)
Stroma H2 O
ADP H2 O
ADP
ATP
enzymes
enzymes
ATP H2 O P P H2 O
Thylakoids
Where: In the grana (thylakoid membranes)
What happens?
Water (H2O) broken apart
Hydrogen ions; electrons; Oxygen is released as a waste
2) Sunlight & enzymes bond ADP with P to make… ATP and NADPH
End result: ATP, H2, Oxygen

15. 60 seconds: Discuss with your neighbor#3 #2
reactants
products
Are the products of photosynthesis on the left or right of the arrow?
Which reactant(s) are used during the light dependent stage?
Which product(s) are created during the light dependent stage?

16. Stage 2: Light Independent (Calvin Cycle)
Stroma H2 H H
ATP
CO2 C O O
CO2 C O O H2 H H H H2 H C6
H12 O6
enzymes
enzymes
CO2 C O O C
CO2 O O
CO2 C O O H H H2
ATP H H2 H H2 H H C
CO2 O O
What’s the formula for glucose?
Where: Stroma (fluid interior) of chloroplast
What happens?
CO2 taken in and ATP and NADPH from step 1 are used
ATP & enzymes break apart CO2 + H2
C’s, O’s, and H’s recombine into C6H12O6 (Glucose)

17. 60 seconds: Discuss with your neighbor#2 #1
reactants
products
Which reactant(s) are used during the light independent stage?
Which product(s) are created during the light independent stage?

18. Connection between photosynthesis & respiration
Plant Cell
chloroplast
mitochondria
glucose
ATP
chloroplast
mitochondria
glucose
ATP
Plants
Create glucose through photosynthesis
Glucose is used to make ATP through cellular respiration

19. Connection between photosynthesis & respiration
Glucose
(from food)
mitochondria
ATP
Glucose
Animals
Plants create glucose through photosynthesis
Animals eat the plants
Glucose is used to make ATP through cellular respiration

20. Review Which color(s) is/are absorbed by a typical red apple?
Which color(s) is/are reflected by a typical red apple?
Which color light produces the highest rates of photosynthesis?
What is used during the light dependent reactions?
What created during the light dependent reactions?
What is used during the light independent reactions?
What created during the light independent reactions?
True or False: Plants are the only photosynthetic organisms.