1. Bell Work!
What is the Equation for photosynthesis?

2. Photosynthesis
Ch 8.2

3. Light-independent reactions
Photosynthesis
Photosynthesis occurs in two phases.
Light-dependent reactions
light absorbed and converted into chemical energy (ATP and NADPH)
Light-independent reactions
ATP and NADPH used to make glucose

4. Photosynthesis Check! What are the reactants of photosynthesis?
What are the products of photosynthesis?

5. Phase One: Light dependent reactions

6. Phase one: light reactions
The absorption of light is the first step in photosynthesis.
Chloroplasts capture light energy.

7. Chloroplasts Thylakoid- flattened sac like membrane
Granum – Stacks of thylakoids
Stroma – Fluid filled area

8. Electron Transport Light energy excites electrons in photosystem II
Light causes a water molecule to split, releasing an electron into the electron transport system
H+ released into the thylakoid space,
O2 released as a waste product.

9. Light energy excites electrons in photosystem II and also causes a water molecule to split, releasing an electron into the electron transport system, H+ into the thylakoid space, and O2 as a waste product.

10. Electron Transport
The excited electrons move from photosystem II to an electron-acceptor protein in the thylakoid membrane.
The electron-acceptor protein transports the electrons along a series of proteins to photosystem I.

11. The electron-acceptor molecule transfers the electrons along a series of electron-carriers to photosystem I.
The excited electrons move from photosystem II to an electron-acceptor molecule in the thylakoid membrane.

12. Electron Transport
Photosystem I transfers the electrons to a protein called ferrodoxin.
Ferrodoxin is the FINAL ELECTRON ACCEPTOR
Ferrodoxin transfers the electrons to the electron carrier NADP+, forming the energy-storing molecule NADPH.

13. Photosystem I transfers the electrons to a protein called ferrodoxin.
Ferrodoxin transfers the electrons to the electron carrier NADP+, forming the energy-storing molecule NADPH.

14. Chemiosmosis
ATP is produced as a result of the flow of electrons down a concentration gradient
the accumulated protons in the thylakoid space activate ATP synthase, forming ATP in the stroma

16. Light reactions Check! What molecules go into the light reactions?
What molecules come out of the light reactions?
In: water, light, nadp+, ADP
Out: O2 NADPH, ATP

17. Phase Two : The Calvin cycle

18. Bell Work!
Where do the light reactions occur?

19. Calvin Cycle
In the Calvin cycle energy is stored in organic molecules such as glucose.
Occurs in stroma of chloroplast

20. Calvin cycle
Six CO2 molecules combine with six 5-carbon compounds to form twelve 3-carbon molecules called 3-PGA.

21. Calvin cycle
The chemical energy stored in ATP and NADPH is transferred to the 3-PGA molecules to form high-energy molecules called G3P.

22. Calvin cycle
Two G3P molecules leave the cycle to be used for the production of glucose and other organic compounds

23. Calvin cycle
An enzyme called rubisco converts the remaining ten G3P molecules into 5-carbon molecules called RuBP.

24. Calvin cycle
RuBP molecules combine with new carbon dioxide molecules to continue the cycle.

25. Calvin cycle check! What molecules go into the Calvin cycle?
What molecules come out of the Calvin cycle?
In: ATP, Co2, NADPH
Out: G3P, ADP, NADP+

26. Cellular Respiration
Ch 8.3

27. Overview of Cellular Respiration
Section 3
Cellular Energy
Cellular Respiration
Overview of Cellular Respiration
Organisms obtain energy in a process called cellular respiration.
The equation for cellular respiration is the opposite of the equation for photosynthesis.

28. Cellular respiration occurs in two main parts.
Section 3
Cellular Energy
Cellular Respiration
Cellular respiration occurs in two main parts.
Glycolysis (anaerobic)
Aerobic respiration (Krebs cycle and electron transport chain)

29. Section 3
Cellular Energy
Cellular Respiration
Glycolysis
Glucose is broken down in the cytoplasm through the process of glycolysis.
Two molecules of ATP and two molecules of NADH are formed for each molecule of glucose that is broken down.

30. Krebs Cycle Cellular Respiration
Section 3
Cellular Energy
Cellular Respiration
Krebs Cycle
Glycolysis has a net result of two ATP and two pyruvate.
Most of the energy from the glucose is still contained in the pyruvate.
The series of reactions in which pyruvate is broken down into carbon dioxide is called the Krebs cycle.

31. Section 3
Cellular Energy
Cellular Respiration
The net yield from the Krebs cycle is six CO2 molecules, two ATP, eight NADH, and two FADH2.

32. Final step in the breakdown of glucose
Section 3
Cellular Energy
Cellular Respiration
Electron Transport
Final step in the breakdown of glucose
Point at which ATP is produced
Produces 24 ATP

33. Anaerobic Respiration
Section 3
Cellular Energy
Cellular Respiration
Anaerobic Respiration
The anaerobic pathway that follows glycolysis
Two main types
Lactic acid fermentation
Alcohol fermentation