1. BIOENERGETIC REACTIONS

2. Photosynthesis

3. Overview All energy on earth comes from the sun. Humankind depends on:
Plants
Algae
Cyanobacteria (photosynthetic bacteria)
to provide this energy for us!

5. Carbon dioxide and water are taken in by plants
Plants absorb light energy from the sun and convert it to a usable form (ATP)
Energy is used to produce sugar molecules which are a useful form of chemical energy
Sugar is converted to starch and stored for use by the plant.

6. Chloroplasts Have TWO membranes
The inner membrane is called the thylakoid.
The thylakoid is folded and looks like stacks of coins called granum.
The stroma is the space surrounding the granum

7. Chloroplasts
Chlorophyll molecules are embedded in the thylakoid membrane
Act like a light “antenna”
These molecules can absorb the sun’s energy.

8. Light Dependent Reactions
Happen ONLY in sunlight.
Light is absorbed by chlorophyll molecules.
The energy generates molecules of ATP

9. Light Independent Reactions
Happen in sunlight, and in the dark.
ATP generated by the LDR drives the Calvin Cycle.
Glucose is a product.
Glucose can be used to “build” starches.

10. Overall Reaction What is the equation for photosynthesis?
carbon dioxide + water  glucose + oxygen + energy
6CO H2O  C6H12O O2 + energy

11. Summary

12. THE REACTIONS
Photosynthesis uses light-dependent and light independent reactions (i.e. the Calvin cycle)
L.D.R occur in the thylakoid and produce ATP and oxygen.
The L.I.R. (Calvin cycle) uses ATP and NADPH to produce high energy sugars.

13. BIOENERGETIC REACTIONS

14. Cellular Respiration

15. Both photosynthesis and cellular respiration provide energy for life.
Both photosynthesis and cellular
respiration provide energy for life.
Photosynthesis uses solar energy to produce glucose and oxygen from carbon dioxide and water
6CO2 + 6H20 + Energy C6H12O6 + 6O2
Occurs in chloroplasts

16. Cellular respiration produces ATP and consumes oxygen during the production of glucose to form carbon dioxide and water
C6H12O6 + 6O CO2 + 6H2O + ATP
Occurs in mitochondria

17. + Sunlight energy ECOSYSTEM Photosynthesis in chloroplasts Glucose CO2
ATP
ECOSYSTEM
Sunlight energy
Photosynthesis in chloroplasts
Cellular respiration in mitochondria
(for cellular work)
Heat energy +

18. What is the relationship between respiration and cellular respiration?
CO2 O2
Bloodstream
Muscle cells carrying out
Cellular Respiration
Breathing
Glucose + O2
CO2 +H2O +ATP
Lungs

19. Both plant and animal cells carry out the final stages of cellular respiration in their mitochondria.

20. Glucose is the main energy source used by all cells.
Cells don’t “burn” glucose. Instead, they gradually release the energy from glucose and other food compounds.
This process begins with a pathway called glycolysis.

21. Stage 1 – Glycolysis Occurs in the cytoplasm An anaerobic process
Stage 1 – Glycolysis
Occurs in the cytoplasm
An anaerobic process
Breaks down glucose into pyruvic acid
Produces a net gain of 2 ATP molecules

22. Stage 2– Krebs Cycle An aerobic process – oxygen IS required
Occurs in the mitochondria
An aerobic process – oxygen IS required
Produces 2 ATP
Begins with pyruvic acid

23. Stage 3 – Electron Transport Chain (ETC)
Uses electron carriers to make ATP
Electrons from NADH and FADH2 travel
down the concentration gradient, which
picks up H+ to form H2O.
Produces 32 ATP

24. (per glucose molecule )
PRODUCTION TOTALS
(per glucose molecule )
2 ATP – Glycolysis
2 ATP – Kreb’s cycle
32 ATP – Electron Transport Chain
36 ATP Total for cellular respiration

25. Fermentation is an anaerobic alternative to cellular respiration
Under anaerobic conditions, many kinds of cells can use glycolysis alone to produce small amounts of ATP
2 types – Lactic Acid Fermentation
Alcohol Fermentation

26. Anaerobic Anaerobic Aerobic