1. Photosynthesis

2. Photosynthesis in Overview
Process by which plants and other autotrophs store the energy of sunlight into sugars.
Requires sunlight, water, and carbon dioxide.
Overall equation:
6 CO H20  C6H12O O2
Occurs in the leaves of plants in organelles called chloroplasts.

3. Leaf Structure Most photosynthesis occurs in the palisade layer.
Gas exchange of CO2 and O2 occurs at openings called stomata surrounded by guard cells on the lower leaf surface.
Palisade
Spongy

4. Chloroplast Structure
Inner membrane called the thylakoid membrane.
Thickened regions called thylakoids. A stack of thylakoids is called a granum. (Plural – grana)
Stroma is a liquid surrounding the thylakoids.

5. Pigments Chlorophyll A is the most important photosynthetic pigment.
Other pigments called antenna or accessory pigments are also present in the leaf.
Chlorophyll B
Carotenoids (orange / red)
Xanthophylls (yellow / brown)
These pigments are embedded in the membranes of the chloroplast in groups called photosystems.

7. Photosynthesis: The Chemical Process
Occurs in two main phases.
Light reactions
Dark reactions (aka – the Calvin Cycle)
Light reactions are the “photo” part of photosynthesis. Light is absorbed by pigments.
Dark reactions are the “synthesis” part of photosynthesis. Trapped energy from the sun is converted to the chemical energy of sugars.

8. Light Reactions
Light-dependent reactions occur on the thylakoid membranes.
Light and water are required for this process.
Energy storage molecules are formed. (ATP and NADPH)
Oxygen gas is made as a waste product.

9. Dark Reactions Dark reactions (light-independent) occur in the stroma.
Carbon dioxide is “fixed” into the sugar glucose.
ATP and NADPH molecules created during the light reactions power the production of this glucose.

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ATP to ADP
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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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12. 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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14. How Do We Get Energy From ATP?
By breaking the high- energy bonds between the last two phosphates in ATP
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How Does That Happen?
An Enzyme!
ATPase
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How is ATP Re-Made?
The reverse of the previous process occurs.
Another Enzyme is used!
ATP Synthetase
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17. Cellular Respiration A quick review…
When we eat, we get energy (glucose and other sugars)
Food energy is broken down into usable energy
Energy used to bond phosphate groups to ADP to make ATP

18. Cellular Respiration What is cell respiration???
Respiration: the process of breaking down food molecules into usable energy.
THE GOAL :
Create ATP for cells to use
Free up electrons – have high energy

19. Other Cellular Respiration Facts
Metabolic Pathway that breaks down carbohydrates
Process is Exergonic as High-energy Glucose is broken into CO2 and H2O
Process is also Catabolic because larger Glucose breaks into smaller molecules
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20. Where Does Cellular Respiration Take Place?
It actually takes place in two parts of the cell:
Glycolysis occurs in the Cytoplasm
Krebs Cycle & ETC Take place in the Mitochondria
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21. What are the Stages of Cellular Respiration?
Glycolysis
The Krebs Cycle
The Electron Transport Chain
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Glycolysis Summary
Takes place in the Cytoplasm
Anaerobic (Doesn’t Use Oxygen)
Requires input of 2 ATP
Glucose split into two molecules of Pyruvate or Pyruvic Acid
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Glycolysis Summary
Also produces 2 NADH and 4 ATP
Pyruvate is oxidized to Acetyl CoA and CO2 is removed
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Fermentation
Occurs when O2 NOT present (anaerobic)
Called Lactic Acid fermentation in muscle cells (makes muscles tired)
Called Alcoholic fermentation in yeast (produces ethanol)
Nets only 2 ATP
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