1. Photosynthesis
Chapter 8

2. In Your Notebook 1. What are the benefits of having a bank account?
Suppose you earned extra money by having a part-time job. At first, you might be tempted to spend all of the money, but then you decide to open a bank account.
1. What are the benefits of having a bank account?
2. What do you have to do if you need some of this money?
3. What might your body do when it has more energy than it needs to carry out its activities?
4. What does your body do when it needs energy?

3. Chapter Mystery Read the chapter mystery on page 225.
Answer the following in your notebook:
Predict how the willow tree gained the extra 75 kilograms in Jan van Helmont’s investigation.
What process occurring at the cellular level in the plant might be connected to its gain in mass?

4. 8.1 Energy and Life Energy is the ability to do work Cars need fuel
Appliances need electricity
Do living things need energy?
Playing sports
Sleeping?
Read 3rd paragraph on page 226
“Energy comes in many forms…….”

5. ATP Adenosine Triphosphate Chemical fuel for our body
We use it to store and release energy

6. Storing Energy ADP – Adenosine Diphosphate Contains some energy
Like a partially charged
battery
Add more energy
by adding phosphates

7. Releasing Energy
ATP can release and store energy by breaking and re-forming the bonds between its phosphate groups.

8. In Your Notebook
Read “Using Biochemical Energy” on page 227 in your book.
Answer the following in your notebook:
With respect to energy, how are ATP and glucose similar?
How are they different?

9. Heterotrophs and Autotrophs
Where do living things get the energy they use to produce ATP?
Chemical compounds found in food
Heterotrophs
Eat plants or eat animals that eat plants
Mushrooms – decompose other organisms
Autotrophs
Make their own food
Use energy from sun to produce high energy carbohydrates - photosynthesis

10. 8.1 Review – In Your Notebook
Create a newspaper-style comic strip that shows how cells use ATP to get the energy they need to carry out cell activities.
Include how ATP molecules store and release energy.
Should be at least 3-5 panels long
Draw cartoon figures to the best of your ability

11. 8.2 Trapping Energy In Your Notebook
Have you ever used a solar-powered calculator? No matter where you go, as long as you have a light source, the calculator works. You never have to put batteries in it.
1. A solar-powered calculator uses solar cells that are found in rows along the top of the calculator. Into what kind of energy is the light energy converted so that the calculator works?
2. Most plants, no matter what size or shape they are, have some parts that are green. Which parts of a plant are usually green?
3. What does the green color have to do with the plant’s ability to convert light energy into the energy found in the food it makes?

12. Chlorophyll vs. Chloroplast
An organelle found in plants
Chlorophyll
A pigment found in chloroplasts
Used to capture energy from sunlight
Three types
Chlorophyll A
Chlorophyll B
Carotenoids

13. Pigments Why do leaves look green?
Why do they turn colors in the fall?

14. Chloroplasts Double membraned organelle
Has saclike membranes called thylakoids
Stacks of thylakoids are called grana
Fluid portion is stroma

15. Energy Collection
Chlorophyll is really good at absorbing visible light
The energy is quickly and efficiently transferred to electrons
Energy levels of electrons gets raised
They get excited
These high energy electrons make photosynthesis work

16. In Your Notebook
In your own words, explain why most plants will not grow well if kept under green light.

17. Photosynthesis Overview
Photosynthesis uses the energy of sunlight to convert water and carbon dioxide (reactants) into high-energy sugars and oxygen (products).
In Symbols
6CO2 + 6H20 light C6H12O6 + 6O2
In Words
Carbon dioxide plus water in the presence of light yields sugars and oxygen

18. Mystery Clue Answer the following in your notebook:
Van Helmont concluded that water must have provided the extra mass gained by the tree. Further studies would prove that he had only half of the answer. What reactant involved in the photosynthesis equation was he not accounting for?

19. Light-Dependent Reactions
Requires direct involvement of light and light absorbing pigments
Use energy from sun to produce ATP and NADPH
Happens in thylakoid membrane of chloroplast
Requires water
Provides electrons to get excited
Oxygen is byproduct

20. Light-Independent Reactions
No light required
Energy from dependent reactions used to make sugars from carbon dioxide
Happens in stroma
AKA – Calvin Cycle

21. 8.2 Review In Your Notebook
Choose two of the following elements of photosynthesis:
Sunlight
Chlorophyll molecule
Chloroplast
High-energy electrons
Light-dependent reactions
Light-independent reactions
Imagine you are the chosen element and offer a first-person explanation of how you are involved in the process of photosynthesis.

22. 8.3 Factors Affecting Photosynthesis
Temperature
Enzymes work best at 0o-35oC
Too high or too low enzymes break down
Light Intensity
More light – more photosynthesis
Eventually reaches maximum
Water
Source of electrons
No water – no electrons
Also causes tissue damage

23. Extreme Conditions When hot, must conserve water
Plants close stomata so water doesn’t escape but that means carbon dioxide can’t get in so plant can’t make sugars
C4 Photosynthesis
Don’t use traditional Calvin Cycle
Allows sugars to be made in intense light and high temperatures
Takes extra energy (ATP)
Corn, sugar cane and sorghum
CAM Plant
Only open stomata at night to let air in
Pineapple and cacti

24. Cellular Respiration How do you feel when you are hungry?
Weakness is your body’s way of telling you that your energy supplies are low.
How do you restore those energy supplies?
In Your Notebook
Read “Chemical Energy and Food” on pg 250
Look at the analyzing data box on page 251
Answer the questions in your notebook

25. Cellular Respiration
Process that releases energy from food in the presence of oxygen
In Symbols
6O2 + C6H12O CO2 + 6H2O + Energy
In Words
Oxygen plus glucose yields carbon dioxide, water and energy
Seems simple, but can’t happen in one big explosion has to be controlled so energy isn’t wasted

26. Stages of Cellular Respiration
Glycolysis
Glucose converted to pyruvic acid
90% of energy still unused
Happens in cytoplasm
Krebs Cycle
Pyruvic acid is broken down into
carbon dioxide
Also produces very little energy
Happens in mitochondria
Electron Transport
Uses high-energy electrons from glycolysis and Krebs cycle to convert ADP into ATP
Requires oxygen as an electron acceptor

27. Oxygen and Energy Respiration = breathing
Cellular respiration = energy releasing pathways in cell
Most of the energy-releasing pathways within cells require oxygen, and that is the reason we need to breathe, to respire
Two types of respiration
Aerobic
Cellular respiration that requires oxygen
Krebs cycle and electron transport chain
Anaerobic
Doesn’t require oxygen
Glycolysis

28. Photosynthesis vs. Cellular Respiration
Photosynthesis removes
carbon dioxide from the
atmosphere, and cellular
respiration puts it back.
Photosynthesis releases
oxygen into the atmosphere,
and cellular respiration uses
that oxygen to release energy
from food

29. In Your Notebook Write the equation for photosynthesis.
Write the equation for cellular respiration.
Explain how these two equations are related.
Be sure to identify which equation is which – you may use symbols