1. Photosynthesis
&
Cellular Respiration

2. Autotrophs & Heterotrophs
An organism that makes its own food is called an autotroph.
An organism that cannot make its own food is called a heterotroph.
Nearly all living things get their energy directly or indirectly from photosynthesis.

3. Photosynthesis
The process by which a cell captures energy in sunlight and uses it to make food.
The raw ingredients that go into the plant cells are water and carbon dioxide
The sunlight energy chemically changes the ingredients into food (glucose)
CO2

4. Photosynthesis Water is absorbed by the roots.
Carbon dioxide gas is taken from the air
Glucose is stored and used by the plant
Oxygen is released into the air

5. The chemical formula for photosynthesis looks like this:
Energy
6H2O + 6CO2
(Sunlight)
C6H12O6 + 6O2
(water)
(carbon dioxide)
(glucose)
(oxygen) O2
CO2

6. Photosynthesis occurs in the chloroplasts of plant cells.
Chlorophyll is the energy absorbing green pigment found in chloroplasts.

7. Gas Exchange
Gasses (CO2 & O2) go in and out of leaves through little holes called stomata.
Sometimes water vapor escapes the stomata through a process called transpiration.
Where is CO2 found in abundance?

8. Guard cells control when the stomata open and close.

9. Since leaves can lose water through stomata, on what part of the leaves do you think stomata can be found?
Make a prediction.

10. Stomata are mostly found on the underside of leaves
Stomata are mostly found on the underside of leaves. This helps the plant lose less water.

11. Cellular Respiration
The process by which cells obtain energy from glucose.
Respiration means “breathing”
This chemical reaction takes place in the matrix of the mitochondria

12. Cellular Respiration
Glucose chemically reacts with Oxygen to form the energy molecule ATP
ATP (energy)
C6H12O6 (glucose)
H2O (water)
O2 (oxygen)
CO2(Carbon dioxide)

13. The chemical formula for cellular respiration looks like this:
+ 6H2O + 6CO2
Energy
C6H12O6 + 6O2
(ATP)
(water)
(carbon
dioxide)
(glucose)
(oxygen)
Does this look familiar?
6H2O + 6CO2
+ Energy
C6H12O6 + 6O2
(water)
(carbon dioxide)
(Sunlight)
(glucose)
(oxygen)

14. The Cycle of Cellular Energy in Plants
• The products made by the chloroplasts are used by the mitochondria.
• The products made by the chloroplasts are used by the chloroplast.
Why don’t animal cells have this cycle?

15. Fermentation provides energy for cells without using oxygen.
Deep water organisms
Yeast (alcohol is byproduct)
Muscle Cells (lactic acid is a byproduct = sore muscles)