1. Cells and Energy

2. Cells require energy in order to perform their functions.
Inside the mitochondria are molecules of adenosine triphosphate (ATP).

3. The ATP – ADP Cycle ATP supplies the energy to keep reactions going.
The bonds between the 2nd and 3rd PO4 are high energy bonds.

4. ATP → ADP + P + energy
When they are broken, a large amount of energy is released.

5. ADP + P + energy → ATP
In order to store energy, energy from food is used to bond a P back to ADP.

6. The ATP cycle is like a constantly recharging battery.

8. Photosynthesis (how energy is trapped)
ATP plays a role in the capturing of sun energy by green plants - photosynthesis

9. Photosynthesis requires light, chlorophyll, and raw materials (CO2 and H2O).
Enzymes are needed for these reactions to proceed. Enzymes speed up reactions without becoming part of the reaction.
This summary does not show many of the individual reactions.

11. The light for photosynthesis is white light, broken into the colors of the visible spectrum.

12. Green plants absorb photons (light energy units) of violet, blue, and red.
The reflect green light which is picked up by our eyes so we see them as green.

13. Chlorophyll is the chemical (pigment) that absorbs the light.
Plants contain chlorophyll A and B.

14. When a photon strikes the chlorophyll molecule, the energy is transferred to an electron of the chlorophyll molecule
This raises the electron to a higher level temporarily. (energized)
When it returns to its original level, it releases the “trapped” energy.

15. Leaf cells with chloroplasts
cell wall
chloroplast
nucleus
cytoplasm
vacuole

16. Photosynthesis takes place in the chloroplast of cells.12
sunlight
palisade cell
of leaf
water
in the chloroplast,
carbon dioxide and
water combine to
make sugar
carbon dioxide

17. The process of photosynthesis can be divided into two steps:
Light (dependent) reaction
requires light
splits H2O and traps energy
Calvin Cycle
Called light independent reactions or dark reactions
does not require light
uses CO2 and the energy and 2H from the light reactions

18. Reactants
Glucose
Products
High Energy
Carbohydrates

19. The Light Reactions -requires light and H2O
sunlight
(photons) ▼▼
energized
chlorophyll
H2O ADP + P → ATP
2H O2 (released)
picked
up by a
H acceptor

20. Light energy is absorbed by chlorophyll found in the chloroplast of plants.

21. H acceptor

22. The Dark Reactions or the Calvin Cycle - does not require light - uses CO2 and the energy and 2H from the light reactions
CO2
RDP
(5 C sugar)
6 C molecule that is unstable
splits into
PGA and PGA
(phosphoglyceraldehyde 3 C each)
PGA + 2H
(bond accomplished with energy
from ATP → ADP + P )

23. (bond accomplished with energy
PGA + 2H
(bond accomplished with energy
from ATP → ADP + P )
PGAL H2O (released)
glucose RDP
PGAL can be used directly by the plant for food, converted to RDP, or can form glucose.

24. GLUCOSE 18 fruits other sugars energy protein e.g. seed germination
cytoplasm
starch
cellulose
cell walls
storage e.g. starch in potato

25. H acceptor

26. Products
Reactants

27. Why is Photosynthesis important to you?
Do you eat kiwi?
Do you eat bananas?
Do you eat oranges?
Do you eat strawberries?
Do you eat grapes?
Do you eat blueberries?
BREAD?
Do you eat eggs?
Do you eat cheese?
Do you drink milk?
MEAT?
VEGETABLES?

28. Do you eat ANYTHING?
ANYTHING

29. Anything you eat can be traced back to a PRODUCER which can be traced back to the SUN!

30. The SUN is the source of all food energy on Earth!

32. Gimme some fin ………… Noggin…….. Dude!