1. Nature of Energy Energy is all around you!
You can hear energy as sound.
You can see energy as light.
And you can feel it as wind.

2. Nature of Energy You use energy when you: hit a softball.
lift your backpack.
compress a spring.

3. Forms of Energy Chemical Light Heat Electromagnetic Nuclear Mechanical
There are several forms energy can take:
Heat
Electromagnetic
Nuclear
Mechanical
Chemical
Light

4. So…. What is Energy?
Energy- the ability to do work. Can be converted from one type of energy to another.
Ex. Gas in your car is burned to create mechanical energy(motion)
Ex. Solar energy cells turn light energy into electrical energy

5. Nature of Energy
Living organisms need energy for growth and movement. Living organisms mainly use Light and Chemical Energy.

6. Photosynthesis
Photosynthesis- process in which plants convert light energy into chemical energy(food). Occurs in the leaves of plants in organelles called chloroplasts.

7. Photosynthesis-starts all ecological food webs!

8. Things needed for photosynthesis
SUNLIGHT
Gives the plant energy
CHLOROPHYLL
The green stuff in chloroplasts that convert light energy to chemical energy by combining water (H2O)and carbon dioxide (CO2) to create glucose (C6H12O6)
WATER
Travels up from the roots
CARBON DIOXIDE
Enters the leaf through small holes on the underneath

9. How do we know that plants make food from just carbon dioxide, water and light energy?
Experiments!!
For example:
Jan Baptist van Helmont (1648) planted a willow tree weighing 5 pounds into 200 pounds of soil and then after 5 years the tree weighed 169 pounds and the soil was still nearly 200 lbs.

10. Photosynthesis Equation
CO2 + H2O  C6H12O6 + O2
6CO2 + 6H2O  C6H12O6 + 6O2
Water(6 H2O) carbon dioxide(6 CO2) glucose(C6H12O6) oxygen(6 O2)

11. Starch, Protein and Oil Synthesis
Glucose is a short term energy molecule for plants when burned up by cellular respiration in mitochondria
Plants convert glucose to starches, proteins and oils for storage by a process called dehydration synthesis. This process occurs in plastids in the cell.

12. How do Cells get Energy?
Energy for living things comes from food. Originally, the energy in food comes from the sun. Whether you are an autotroph- make your own food or a heterotroph- eat your food … All organisms burn up food for daily energy needs.

13. Types of Food(Macromolecules)
Proteins- digested into amino acids
Lipids- digested into fatty acids and glycerol
Carbohydrates- digested into glucose
All 3 types of food can be used for energy, but glucose is the main energy molecule used.

14. Cells Use Energy
Cells cannot use glucose directly for energy. Glucose must be converted into another energy molecule called ATP, Adenosine Triphosphate
The conversion of glucose to ATP occurs in the mitochondria and is called cellular respiration.

15. Cellular Respiration- burning up glucose to create ATP
Burning something requires oxygen
Organisms take in oxygen(O2) so they can burn up glucose during cellular respiration.

16. Cellular Respiration Equation
C6H12O6 + O CO2 + H2O
C6H12O O CO H2O
So…. Where’s the ATP ??
Glucose(C6H12O6) oxygen (O2) water(H2O) carbon dioxide(CO2)

17. Cellular Respiration Equation
C6H12O O CO H2O
The ATP energy is produced by splitting the glucose molecule. It takes 2 ATP molecules to split the high energy bond of glucose, releasing 38 ATP molecules. 38 ATP – 2 ATP = a net of 36 ATP 36
Net ATP =
2 ATP

18. Pause for a moment…?? “the circle of life” C6H12O6 + 6O2 6CO2 + 6H2O
Cellular respiration
C6H12O O CO H2O
Where have I seen these letters before???
They look so familiar??? … I know, I remember …..
The equation for cellular respiration is the exact opposite of the equation for photosynthesis. Isn’t life symmetrical!!
Photosynthesis
6CO H C6H12O O2
“the circle of life”

19. Cellular Respiration Equation
C6H12O O CO H2O
This type of cellular respiration is called Aerobic Respiration- converting glucose to ATP in the presence of oxygen. Produces 36 molecules of ATP 36
Net ATP =
2 ATP

20. Electron Transport Chain
Aerobic Respiration mostly occurs in the mitochondria
Electrons carried in NADH
Mitochondria
In Cytoplasm
Electrons carried in NADH and FADH2
Krebs Cycle
Electron Transport Chain
Glucose
Glycolysis 2 2 32

21. Anaerobic Respiration: occurs when no oxygen is available to the cell (2 kinds: Alcoholic and Lactic Acid)
Also called fermentation
Much less ATP produced than in aerobic respiration

22. Alcoholic fermentation—occurs in bacteria and yeast
Process used in the baking and brewing industry—yeast produces CO2 gas during fermentation to make dough rise and give bread its holes
glucose ethyl alcohol + carbon dioxide + 2 ATP

23. Lactic acid fermentation—occurs in muscle cells
Lactic acid is produced in the muscles during rapid exercise when the body cannot supply enough oxygen to the tissues—causes burning sensation in muscles
glucose lactic acid + carbon dioxide + 2 ATP

24. How do Cells Use ATP
All energy is stored in the bonds of compounds—breaking the bond releases the energy. Breaking the bond on the 3rd phosphate releases energy for the cell to use.
When the cell has food energy available it can “recharge” the molecule by adding a phosphate group back to ADP, producing ATP

25. Energy from ATP is released for when a phosphate molecule is removed creating a lower energy molecule called ADP.

26. Energy from glucose(cellular respiration) is used to push the loose phosphate molecule back to create high energy ATP.

27. Overview of photosynthesis and respiration
SUN
Would anyone like to sing “The Circle of Life”??
RADIANT ENERGY
CELL
ACTIVITIES
PHOTOSYNTHESIS
RESPIRATION
GLUCOSE
ATP(ENERGY)