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ATP & Photosynthesis
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What Is ATP?
Energy used by all Cells
Adenosine Triphosphate
Organic molecule containing high-energy Phosphate bonds
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3. Chemical Structure of ATP
Adenine Base
3 Phosphates
Ribose Sugar
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What Does ATP Do for You?
It supplies YOU with ENERGY!
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5. How Do We Get Energy From ATP?
By breaking the high- energy bonds between the last two phosphates in ATP
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The ADP-ATP Cycle
Releases energy
Stores energy
ATP Synthetase
Helps to re-create bond
ATP-ase
Helps to break bond
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7. Photosynthesis
Photosynthesis nourishes almost all of the living world directly or indirectly.
Autotrophs make their organic molecules from CO2 and water obtained from the environment.
Autotrophs are the ultimate sources of organic compounds for all heterotrophic organisms.
Autotrophs are the producers of the biosphere

8. Heterotrophs consume organic compounds produced by other organisms.
These organisms are the consumers of the biosphere.
The most obvious type of heterotrophs feed on plants (herbivores) and other animals (carnivores).
Other heterotrophs (saprophytes) decompose and feed on dead organisms and on organic litter, like feces and fallen leaves.
Almost all heterotrophs are completely dependent on photoautotrophs for food and for oxygen, a byproduct of photosynthesis.

9. Chloroplasts are the sites of photosynthesis in plants
Any green part of a plant has chloroplasts but the leaves are the major site of photosynthesis for most plants.
The color of a leaf comes from chlorophyll, the green pigment in the chloroplasts.
Chlorophyll is a pigment molecule that is important in the absorption of light energy during photosynthesis.

10. Chloroplasts
Chloroplasts are found mainly in mesophyll cells forming the tissues in the interior of the leaf.
O2 exits and CO2 enters the leaf through microscopic pores, stomata, in the leaf.
Veins deliver water from the roots and carry off sugar from mesophyll cells to other plant areas.

11. Structure of the chloroplast
Each chloroplast has two membranes (inner & outer) around a central liquid space, the stroma.
In the stroma are green membrane sacs, called thylakoids.
Thylakoids may be stacked into columns called grana.

12. The Photosynthesis Reaction
Using light energy, chloroplasts produce sugar and O2 from CO2 and H2O.
the equation describing the process of photosynthesis is:
6CO2 + 6H2O in presence of light and chlorophyllC6H12O6 + 6O2

13. Photosynthesis is actually two processes, each with multiple stages.
The light reactions convert light energy to chemical energy using chlorophyll.
The Calvin cycle changes CO2 from the atmosphere into an organic molecule and uses energy from the light reaction to create the sugar.

14. The light reaction also recharges ADP to ATP for the Calvin cycle
In the light reaction light energy absorbed by chlorophyll in the thylakoids starts the transfer of electrons and hydrogen from water to NADP+, forming NADPH.
NADPH, an electron and proton acceptor, transfers energized electrons from the the light reactions to the Calvin cycle.
The light reaction also recharges ADP to ATP for the Calvin cycle

15. Calvin cycle reactants: carbon dioxide, ATP, NADPH
Light reaction reactants: water, ADP +P, NADP+
Calvin cycle products: sugar, ADP +P, NADP+
Light reaction products: oxygen, ATP, NADPH

16. The Calvin cycle is named for Melvin Calvin who, with his colleagues, worked out many of its steps in the 1940s.
While the light reactions occur at the thylakoids, the Calvin cycle occurs in the stroma (no light needed).
There are three main stages to the Calvin cycle:
Carbon fixation - carbon dioxide is changed into organic carbon compounds.
Reduction -NADPH provides electrons and H to continue the forming of the sugar molecule.
ATP from the light reaction provides energy for the Calvin cycle to assemble the sugar.

17. Regeneration of cycle carrying molecules
In total, to make 1 molecule of glucose it requires:
6 molecules of CO2
6 molecules of H2O
9 molecules of ATP
6 molecules of NADPH
And 6 molecules of O2 are released as a waste product

18. Many plants make more sugar than they need
The excess is stored in roots, tuber, and fruits
These are a major source of food for animals
Main Factors that limit the rate of photosynthesis
Light intensity
If intensity is too great photosynthesis levels off
Amount of carbon dioxide present
If CO2 level drops photosynthesis slows
Temperature
Since enzymes are involved in reactions temperature must be kept in range