1. Photosynthesis and Cellular Respiration

2. ATP: adenosine triphosphate
--main energy molecule for cells
--recycled in the cell
--made of adenosine and 3 phosphates
All organisms require energy for
Active transport
Cell division
Movement
Production of proteins

3. Photosynthesis Process that uses the sun’s energy to make glucose
Carried out by green plants and some bacteria (autotrophs)
Purpose is to trap sun’s energy and store it in glucose (food for the plant)
Photosynthesis occurs in the chloroplast

4. Photosynthesis Chloroplast Structure:
Stroma: Space inside the chloroplast
Thylakoid: Green disk in the chloroplast
Granum stack: Stack of green thylakoids

5. Chloroplasts Thylakoids are green because they contain chlorophyll
Chlorophyll: green pigment in plants that absorbs light energy
Looks green because it reflects green light and absorbs other wavelengths (colors)
Pigment: light-absorbing compound

6. Overall Reaction 6CO2 + 6 H2O + light energy → C6H12O6 + 6O2
Carbohydrate made is glucose

7. Steps of Photosynthesis
1. Light reaction (Light-dependent reaction)
--First step of photosynthesis that traps sunlight and makes electrons and ATP to run the dark reaction
--occurs in the thylakoids
2. Dark reaction (Light-independent reaction)
--Second step of photosynthesis that uses ATP and electrons from the light reaction and carbon dioxide from the air to make glucose
--occurs in the stroma

9. Harvesting Chemical Energy
energy enters food chains (via autotrophs)
how do organisms use that energy to fuel their bodies
Plants and animals both use products of photosynthesis (glucose) for fuel
Heterotrophs: must take in energy from outside sources, cannot make their own e.g. animals
When we take in glucose (or other carbs), proteins, and fats-these foods don’t come to us the way our cells can use them

10. Cellular Respiration
The process by which mitochondria break down glucose to make ATP
Two types
Aerobic respiration: requires oxygen and carried out by plants, animals, and some bacteria
Anaerobic respiration: requires no oxygen and carried out by yeast, some bacteria, and sometimes animals

11. Cellular Respiration
These reactions proceed the same way in plants and animals.
Overall Reaction:
C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP

12. Mitochondria Aerobic respiration occurs in the mitochondria
Makes energy for the cell through aerobic respiration
Structure of a mitochondria
Inner membrane
Outer membrane
Cristae: Fold in the inner membrane

13. Steps of aerobic respiration
1. Glycolysis: First step breaks down glucose into pyruvate
--(Intermediate step: Change pyruvate to acetyl CoA)
2. Citric Acid Cycle: Second step uses the acetyl CoA to make electrons for the last step
3. Electron transport chain: Third step uses the electrons to make a lot of ATP (36)

15. Anaerobic Cellular Respiration
Some organisms thrive in environments with little or no oxygen
Marshes, bogs, gut of animals, sewage treatment ponds
No oxygen used= ‘an’aerobic
End products such as ethanol and CO2 (single cell fungi (yeast) in beer/bread) or lactic acid (muscle cells)

16. Anaerobic respiration (requires no oxygen)
Also called fermentation
2 types: alcoholic fermentation and lactic acid fermentation
Only 2 ATP are made in anaerobic respiration so it is not as good as aerobic respiration (36 ATP)
Both begin with glycolysis
No citric acid cycle or electron transport chain

17. Alcoholic fermentation
Pyruvate  ethyl alcohol + carbon dioxide
Carried out by yeast and some bacteria
Used in brewing beer, making wine, and baking bread and cakes

18. Lactic acid fermentation
Pyruvate  lactic acid
Carried out by your muscles when you’re exercising hard (need ATP) and can’t get oxygen into you fast enough (can’t do aerobic respiration)
Causes muscle cramps and soreness

20. Energy Tally 36 ATP for aerobic vs. 2 ATP for anaerobic
Glycolysis ATP
Kreb’s ATP
Electron Transport 32 ATP
36 ATP
Anaerobic organisms can’t be too energetic but are important for global recycling of carbon

21. Photosynthesis and respiration are the opposite of each other
Plants -- chloroplast
* use sunlight to make glucose
* take in carbon dioxide
* give off oxygen
*carbon dioxide + water + sunlight  glucose + oxygen
Respiration
Animals and plants -- mitochondria
* eat plants to get glucose
* take in oxygen
* give off carbon dioxide
*glucose + oxygen  carbon dioxide + water + ATP