1. Photosynthesis/Chemosynthesis

2. Autotrophs:
Organisms that are capable of producing/creating their own food
Photoautotrophs – sunlight drives the energy production process
Chemoautotrophs – can extract energy from an inorganic substance

3. heterotrophs
Organisms that need to get their energy from organic compounds already put together by other organisms

4. Photosynthesis
Method by which autotrophs use their energy from the sun to create carbon compounds and energy rich molecules

5. Key Concepts
Carbon-based compounds are the building block of energy stores
Plants assemble these compounds through photosynthesis

6. Process Overview Water + Carbon Dioxide  Oxygen + Glucose
12 H2O+ 6 CO2  6 O2 + C6H12O6 + 6 H2O
Sunlight is trapped and converted into chemical energy (ATP)
ATP delivers energy to reactions that create glucose
Glucose units are combined to create starch and other materials

7. 1st Stage: Light Dependent Reactions
Energy from the sun is captured and converted to ATP
Water molecules are split
Coenzyme (substance that aids an enzyme in reactions) NADP+ picks hydrogen particles and electrons forming NADPH (electron carrier)

8. 2nd Stage: Light Independent Reactions
ATP donates energy so glucose can be formed from carbon, hydrogen, and oxygen
The carbon and oxygen comes from carbon dioxide
The hydrogen comes from the water via NADPH

9. Chloroplast
Photosynthetic organelle found in photoautotrophs, site of photosynthesis

10. Stroma
The interior of the chloroplast that contains the grana

11. THYLAKOID
Flattened discs whose stacks are called the Granum/Grana

12. Pigments
Molecules that absorb light
Chlorophyll is the main pigment

13. Light Dependent Reactions – In Depth
1st stage of Photosynthesis:
Pigments absorb sunlight and release electrons
Electrons and hydrogen ions transfer energy that leads to ATP and NADPH formation
The pigments that gave up electrons in the first place get electron replacements

14. Non-Cyclic ATP Formation
Photolysis: water molecules are split into oxygen, hydrogen ions, and electrons
Oxygen released as a waste product
The abundance of hydrogen ions creates an electrical/concentration gradient inside the thykaloid
Combined force of gradients pumps ions out into stroma creating energy needed to create ATP out of ADP

15. Light Independent Reactions – In Depth
2nd Stage of Photosynthesis: “Calvin Benson Cycle”
ATP molecules deliver energy
ATP and NADPH molecules deliver the required hydrogen and electrons
Carbon Dioxide provides the needed carbon and oxygen
Can proceed in the dark as long as the above substrates are present

16. Calvin Benson Cycle:
Carbon Dioxide diffuses across the membrane and is fixed to a five carbon compound (carbon fixation)
This unstable six carbon compound is broken down and reformed into a six carbon sugar which can be formed into sucrose, starch, cellulose, etc.

17. Effects of the Environment
A) Light Intensity– as light intensity increase so does the rate of photosynthesis till all the pigments reach a saturation point
B) Concentration of Carbon Dioxide – As CO2 concentration increases so does the rate of photosynthesis till all structures are being used at which point it levels out
C) Temperature – There is an optimal temperature at which photosynthesis is most efficient, too extreme and it decreases (related to enzymes and water)

18. Chemosynthesis:
Process by which bacteria get energy by pulling hydrogen and electrons from ammonium ions, iron or sulfur compounds, and other inorganic materials
Get carbon from carbon dioxide