1. Photosynthesis & Cellular Respiration

2. Photosynthesis Equation
Uses the energy from sunlight to convert water and carbon dioxide into high-energy sugars and oxygen

3. How do plants get energy from light?
From the chlorophyll!!!
A pigment found in plants
They absorb light

4. How do plants get CO2? Through the stoma in their leaves
Opening at the bottom of a leaf that lets CO2 and O2 to diffuse in and out

5. Sunlight excites electrons in chlorophyll
Electron carriers
Sunlight excites electrons in chlorophyll
Gain energy
Need a special carrier for high-energy electrons
Electron Transport
NADP+ is an electron carrier

6. Anatomy of a Chloroplast
chlorophyll: pigment inside chloroplasts
thylakoid: saclike membranes (light-dependent reactions)
stack of thylakoids
stroma: area outside thylakoid (light-independent reactions)

7. ADP vs. ATP Cells store and release energy with ATP Store=ADP
Release=ATP

8. Photosynthesis

9. Light-Dependent Reaction
Uses ADP+P & NADP+ from the light- independent reactions to carry electrons
6 H2O enter the cycle
Oxygen exits the cycle

10. Photolysis
Light is absorbed and breaks up water molecules into 3 parts:
Energized electrons
Hydrogen ions (H+)
Oxygen (O2)

11. Calvin Cycle
Uses ATP & NADPH from the light- dependent reactions to make high-energy sugars (Glucose)
6 CO2 enter the cycle
ATP goes in (gives energy) and NADPH goes in (donates electrons)
Glucose exits the cycle

13. What can limit photosynthesis?
Light intensity
Carbon dioxide concentration
Temperature

14. Cellular Respiration

15. Cellular Respiration
Releases energy by breaking down glucose (or other food molecules) in the presence of oxygen
Aerobic
Responsible for most of our stored energy
All living things do this!

16. Anatomy of Mitochondria
Two membranes
Cristae-Electron Transport Chain
Matrix-Krebs Cycle

17. Chemical Energy
ATP: adenosine triphosphate – chemical compound used to store & release energy
breaking this bond releases energy
when one P is removed, energy is released
ATP ADP + P

18. Step 1: Glycolysis
One molecule of glucose is broken in ½ making two molecules of pyruvic acid
Release ATP & NADH

19. Step 2: Krebs Cycle Pyruvic acid is broken down into CO2
Occurs in the matrix
Goes through this cycle twice!
High-energy electrons are picked up by carriers and taken to the Electron Transport Chain

20. Step 3: Electron Transport Chain
Uses high-energy electrons from Krebs Cycle to convert ADP to ATP
Occurs in the cristae!
O2 is the final electron acceptor in the chain-> makes water
Most ATP is made in this step!

21. Photosynthesis vs. Cell Respiration
You decide!

22. Fermentation

23. What happens if we don’t have Oxygen?
Fermentation!
Release energy from food molecules by producing ATP without O2
Anaerobic (without oxygen)
There are 2 main types:
Alcoholic fermentation
Lactic Acid fermentation

24. Alcoholic Fermentation
Yeast and other microorganisms
Ethyl alcohol and CO2 as waste
Causes bread dough to rise
Only 2 ATP are made

25. Lactic Acid Fermentation
Converting pyruvic acid into lactic acid
Muscles, pickles, sauerkraut, sour cream, yogurt, cheese & buttermilk
Only 2 ATP are made

26. Let’s compare!
Anaerobic vs Aerobic Respiration
Running discussion