1. The Working Cell: Energy from Sunlight
Biology
The Working Cell: Energy from Sunlight

2. Photosynthesis evolved ~3 billion years ago
It supports most of life on Earth
It is the conversion of sunlight into a usable form of energy
Pigments are molecules that absorb certain wavelengths of light while reflecting others
Chlorophyll is green (what we see) and absorbs violet, red and blue; this is the main pigment of photosynthesis.

3. There are 2 types of chlorophyll (a & b); chlorophyll a is the primary pigment in all plants and algae
The chloroplast is the organelle that is the location of photosynthesis. There are many chloroplasts within the leaf (the main photosynthetic part of the plant).

4. Chloroplast Double membrane (outer & inner)
Chlorophyll: green pigment within
Thylakoids: disk-shaped structures that contain the enzymes needed for photosynthesis
Grana (sing: granum): stacks of thylakoids (allow for greater surface area)
Stroma: fluid within (surrounding thylakoids)

6. The general equation of photosynthesis: 6CO2 + 6H2O  C6H12O6 + 6O2
Photosynthesis occurs in 2 stages (see fig 8-4):
Light Reactions
Calvin Cycle (a.k.a. Dark Reactions)

7. Photosynthesis Light Dependent Reactions:
These are also known as the Light Reactions
These require light
These require water and sunlight

8. What happens?
Light enters the chloroplast
Water is split, releasing O2 (this is what we breathe)
Electrons become available (to make ATP and NADPH for the Calvin cycle)

9. Photosystems
Photosystem I & photosystem II are located w/in the thylakoids.
Light reactions take place w/in thylakoids
Chlorophyll a is located here
Photosystem II is used 1st; then photosystem I

10. This is a.k.a. the light independent or dark reactions
The Calvin Cycle:
This is a.k.a. the light independent or dark reactions
This requires CO2 (makes the sugar)
This requires ATP and NADPH (which “drives the cycle)

12. 1 glucose is produced for every 6 molecules of CO2 that enter the Calvin Cycle
Actually G3P (glyceraldehyde-3-phosphate) is the product of 1 turn of the Calvin Cycle

13. Global Impact
Carbon cycle: process of C changing from inorganic to organic; movement of Carbon through the ecosystem.
Greenhouse effect: when atmospheric CO2 rises, trapping heat within the Earth’s atmosphere causing the global climate to be warm enough for life (the temp is rising).

14. Primary Production - The conversion of inorganic carbon, usually in the form of carbon dioxide, into organic compounds by autotrophs.

15. Template copyright 2005 www.brainybetty.com
THE END!
11/21/2018
Template copyright

16. This slide show was developed by Dana Halloran,
Cardinal Mooney High School, Sarasota, FL.
Used with her personal permission,
adapted and amended by Rosa Whiting,
Manatee School for the Arts, Palmetto, FL.