1. Chapter 8, section 2: Energy for the Cell
Photosynthesis and
Cellular Respiration

2. Hungry? When you’re hungry, what do you do?
What do we use the food for?
Why do we need the food?
Where do plants get energy?
What is the process called that allows plants to make their food?

3. Photosynthesis Photo=light (capturing light energy)
Synthesis=to make food
Light is absorbed in the chlorophyll of plants; it is the main pigment in photosynthesis.
Chlorophyll provides the plant with it’s green color and is found in the chloroplasts.

4. Photosynthesis: Making Food
Plants use the energy captured by the chlorophyll, and combine carbon dioxide and water to make food.
CO2 + H2O  glucose + O2
This is the act of converting the sun’s energy into chemical energy that can be stored.

5. Re-cap Process of photosynthesis:
Sunlight is captured by the chlorophyll in the _______.
Energy from the sun is used to combine ____ and ____ to make food.
Products of photosynthesis are: _____ and ______.

6. How do we break down the food?
We need to break down our food to give us ______.
There are two ways to do this:
Cellular Respiration
Fermentation

7. Cellular Respiration
…is the breakdown of food, such as glucose, using oxygen.
Think “respiration” and breathing = oxygen
When you breathe in, you are supplying cells with oxygen to break down your food.

8. Fun stuff continued…
Carbon dioxide and water are released during cellular respiration…along with energy.
When you break down something, you are going to have energy as a result.
ATP is the energy in cellular respiration.
ATP fuels activities of the cell.

9. Cellular respiration takes place in mitochondria (“powerhouse”).
Breaks down sugar (glucose), with the help of oxygen.
Carbon dioxide, water and ATP are released during this process.
ATP gives cells energy.

10. What happens if we run out of oxygen?

11. Fermentation Running cramps?
The process of breaking down glucose to energize your cells when you have run out of oxygen.
Leads to a very small production of ATP.
Two types of fermentation: Lactic acid (muscle fatigue after strenuous activity) and yeast (CO2 bubbles and causes yeast to rise)

12. Photosynthesis Chapter 13, section 4
Cellular Respiration
Transpiration

13. Photosynthesis in detail, page 333
Sunlight is converted to chemical energy, and stored as glucose (sugar).
CO2 + H2O  Glucose
CO2 comes from air – enters stomata in the plants leaves.
Water enters through roots (xylem, picture on page 328) to the leaves, where photosynthesis takes place.

14. More detail
Chloroplasts inner membrane forms stacks called grana, which contain the chlorophyll.
In making the sugar, the chlorophyll breaks down water into hydrogen and oxygen, and then the CO2 assists in making the sugar called glucose.
Oxygen is given off as a byproduct.
The loss of water from the leaves is called transpiration.