1. Photosynthesis – what you really need to know…

2. Warm Up #1
Give an example of an autotroph.
List 2 examples of a heterotroph.
Where is the energy stored in an ATP molecule?
What’s wrong with ATP’s energy storing capabilities?

3. Warm Up #2 Write the chemical equation for photosynthesis.
What are the reactants?
What are the products?
Where do the reactants come from?
5. What is the pigment found in plants that give them their green color?

4. Warm Up #3 Name the two cycles of photosynthesis.
Is light required for the light reactions?
Is light required for the Calvin Cycle?
Can the Calvin cycle work if light is present?

5. Energy and Life
Autotroph – organisms that are able to make their own food (plants)
Heterotroph – organisms that must obtain energy from food they consume.

6. Energy in Living Systems
Energy flows through living systems.
You get energy from the food you eat – where does the energy in the food come from?
Energy flows from autotrophs ( organisms that make their own food) to heterotrophs (organisms that rely on others for food).

7. ATP The ultimate source of most energy found on Earth is the sun.
In living things, energy is stored in cells in the mitochondria in the form of ATP (adenosine triphosphate)
ATP has three phosphates – the key to it’s ability to store and release energy lies in the bonds between the phosphates.
mitochondrion

8. ATP Molecule

9. Energy stored in the cell is released gradually in a series of enzyme (protein) assisted reactions.
Energy is stored temporarily in molecules of ATP.
Released energy is enough to process most of the cell’s activities.

10. Storing and Releasing Energy
ADP Adenosine diphosphate – looks like ATP but only has 2 phosphates
This small difference is the key to the energy storing capabilities – ADP adds a phosphate and becomes ATP ( a fully charged battery)

11. Energy is released when the bonds
between 2nd and 3rd phosphates
are broken!

12. PHOTOSYNTHESIS Literally means “put together with light”
Process by which light energy (energy from the sun) is converted into chemical energy (energy we need to survive).
Almost all autotrophs, especially plants are photosynthetic organisms.

13. EQUATION 6CO2 + 6H2O C6H12O6 +6O2 Reactants Products
Light
6CO2 + 6H2O C6H12O6 +6O2
Reactants Products
Carbon Dioxide Glucose (sugar-starch)
Comes from the
atmosphere, Into the
leaves through the stomata
Water Oxygen
Comes from the soil

14. Requirements for Photosynthesis
In order for photosynthesis to occur 4 things must be present:
1. Carbon Dioxide
2. Water
3. Light
4. Chlorophyll – plants principal pigment – gives it a green color. Light is a form of energy – any compound that absorbs light – stores energy

15. Chloroplast: Site of Photosynthesis

17. Steps of Photosynthesis
LIGHT DEPENDENT – requires light to split water molecules producing Oxygen, ATP and NADPH

19. 2. CALVIN CYCLE – does NOT require light, uses Carbon Dioxide (from the atmosphere) , ATP and NADPH to make glucose (simple sugar)

21. Factors affecting photosynthesis…
Temperature – not as much photosynthesis in the winter months because the sun’s rays are not as strong.
Intensity of Light – the more intense the light the more photosynthesis and vice versa
Water & Carbon dioxide availability

22. Why do leaves change color in the fall?
During winter, there is not enough light or water for photosynthesis. The trees will rest, and live off the food they stored during the summer. They begin to shut down their food-making factories. The green chlorophyll disappears from the leaves. As the bright green fades away, we begin to see yellow and orange colors. Small amounts of these colors have been in the leaves all along. We just can't see them in the summer, because they are covered up by the green chlorophyll.

25. The bright reds and purples we see in leaves are made mostly in the fall. In some trees, like maples, glucose is trapped in the leaves after photosynthesis stops. Sunlight and the cool nights of autumn cause the leaves turn this glucose into a red color. The brown color of trees like oaks is made from wastes left in the leaves.

26. occurs in the mitochondria, yields more ATP .
Cellular Respiration
2 types:
1. Aerobic – requires
occurs in the mitochondria, yields more ATP .
2. Anaerobic – does not require oxygen, yields less ATP.

27. Cellular Respiration
C6H12O6 + 6O CO2 + 6H2O
This equation is the exact same as the equation for photosynthesis, except..?
It is reversed!

28. Cellular Respiration 3 Stages of AEROBIC RESPIRATION
1. Glycolysis – “sugar splitting” glucose (sugar) is broken down in the cytoplasm. Yields 2 ATP, occurs in cytoplasm.
DOES NOT REQUIRE OXYGEN. If no oxygen is present the cycle stops here. Occurs in all organisms – heterotrophs and autotrophs.

29. 2 and 3: Krebs Cycle and Electron Transport Chain
Beginning of aerobic respiration
Requires oxygen
Takes place in the mitochondria
ADP is converted to ATP.
The two cycles together produce 34 ATP.
The total of all three parts = 36 ATP

30. Cellular Respiration
ANAEROBIC RESPIRATION- when you work out too much or get physically tired, your cells do not get enough oxygen. This causes them to go through a process called fermentation.

31. 2 Types of Fermentation
Lactic acid
fermentation
- in cytoplasm
2. Alcoholic
- in yeast cells

32. Lactic acid fermentation – occurs in animals, lactic acid is
what makes your muscles
burn, leads to cramping.
Reason you pant after exercise
because your cells are lacking
enough oxygen to
go through aerobic
respiration.

33. 2. Alcoholic Fermentation – process by which beer and wine are made.
Yeast do this!

34. Comparing photosynthesis and cellular respiration
Uses water
Gives off water
Uses carbon dioxide
Gives off carbon dioxide
Makes glucose
Breaks down glucose
Gives off oxygen
Uses oxygen
Takes in energy from the sun
Releases energy
Occurs in chloroplast
Occurs in mitochondria
Occurs in plants, some bacteria and protists
Occurs in all organisms