1. Why do we use it for Energy?
ATP
Why do we use it for Energy?

2. ATP: Adenosine Triphosphate
Consists of Adenosine + 3 Phosphates
Highly unstable molecule
3 phosphates each highly negative repel each other (like the wrong end of a magnet) each phosphate is surrounded by very negative oxygen atoms.
Hence a phosphate group is removed through hydrolysis energy is released (-7.3 kcal/mole) and breaks down into the more stable molecule ADP.
Not a happy molecule
Add 1st Pi  Kerplunk! Big negatively charged functional group
Add 2nd Pi  EASY or DIFFICULT to add? DIFFICULT takes energy to add = same charges repel  Is it STABLE or UNSTABLE? UNSTABLE = 2 negatively charged functional groups not strongly bonded to each other So if it releases Pi  releases ENERGY
Add 3rd Pi  MORE or LESS UNSTABLE? MORE = like an unstable currency • Hot stuff! • Doesn’t stick around • Can’t store it up • Dangerous to store = wants to give its Pi to anything

3. I think he’s a bit unstable… don’t you?
ATP: Pictures
Where does the Negativity come from? Oxygen
I think he’s a bit unstable… don’t you?
Oxygen

4. ATP / ADP cycle Can’t store ATP ATP
good energy donor, not good energy storage
too reactive
transfers Pi too easily
only short term energy storage
carbohydrates & fats are long term energy storage
ATP
cellular respiration
7.3 kcal/mole
ADP Pi +
A working muscle recycles over 10 million ATPs per second
Whoa! Pass me the glucose
(and O2)! 4

5. PHOTOSYNTHESIS .
Chemosynthesis

6. Plants take H2O, Sun, and CO2 to make Glucose the sugar that they use for food and O2 too!

7. CAPTURING THE ENERGY IN LIGHT
The process by which organisms obtain energy directly from sunlight is called photosynthesis.
6CO2 + 6H2O → C6H12O6 + 6O2

8. ENERGY FOR LIFE PROCESSES
Autotrophs: Plants, Algae, and some Bacteria.
Autotrophs store energy in various organic compounds, primarily carbohydrates.

9. Photosynthesis involves a complex series of chemical reactions:
Biochemical Pathway
Products used in cellular respiration.
How it was
Discovered

10. Photosynthesis

11. LIGHT ABSORPTION IN CHLOROPLASTS
Light Reactions or Light Dependent Reactions
They begin with the absorption of light
in chloroplasts.

12. LIGHT AND PIGMENTS

13. chlorophylls
accessory pigments
carotenoids
Chromatography

14. CHLOROPLASTS

15. RESTORING PHOTOSYSTEM II

16. Light Dependent Reaction

17. CHEMIOSMOSIS

18. PUTTING IT ALL TOGETHER
Review of the
Light Reaction
With All
Details!

19. LIGHT INDEPENDENT REACTIONS
KNOWN AS THE CALVIN CYCLE.
CO2 IS FIXED INTO ORGANIC COMPOUNDS: CARBON FIXATION.
THREE MAJOR STEPS, WHICH OCCUR WITHIN THE STROMA.
How do
Plants
Capture
CO2?
Calvin
Cycle

21. RATE OF PHOTOSYNTHESIS