1. Energy in the Cell

2. Energy Energy- the ability to do work or cause change
All energy in living things is as chemical compounds
Main energy source = THE SUN

3. Where Does Energy Come From?
Energy is stored in food!!!
Plants are autotrophs—they make their own food from sunlight.
Animals are heterotrophs- cannot make their own food, must eat food for energy.

4. Chemical Energy 3 main chemical compounds for energy:
ATP (adenosine tri-phosphate)
ADP (adenosine di-phosphate)
Glucose (C6H12O6)- sugar/carbs

5. ATP vs. ADP Break chemical bonds = RELEASE energy
ATP becomes ADP by breaking a phosphate group (P)
Break chemical bonds = RELEASE energy
ADP becomes ATP by adding a phosphate group (P)
Adding chemical bonds = STORE energy

6. Photosynthesis Photo: light Synthesis: make something
The process by which plant cells use light energy to make food
Where: chloroplasts
Who: Chlorophyll- pigment that traps sun’s light energy

7. The Photosynthesis Reaction
6 CO2 + 6 H2O + light energy = C6H12O6 + 6 O2
trapped by chlorophyll
Carbon Dioxide + Water + Sunlight = Glucose + Oxygen
2 stages:
Light Reaction- needs light, oxygen released
Dark Reaction- no light needed, makes sugar

8. Cellular Respiration The opposite of photosynthesis!
Instead of making food, we break down food to release energy
Takes place in mitochondria of all living things
C6H12O O2 = 6 CO2 + 6 H2O + ATP

9. 30 Seconds 10 Time’s Up! 3 Minutes 1 Minute 4 Minutes 1 2 5 2 Minutes
Bellringer 11/112/09
In your next empty square on page 100:
Write the equation for photosynthesis
Write the equation for cellular respiration!
Use your notes from Tuesday!
Reminders: HW #10 due Fri! LAB FEE NOW!
30 Seconds 10
Time’s Up!
3 Minutes
1 Minute
4 Minutes 1 2 5
2 Minutes 8 9 7 6 4 3

10. Cellular Respiration Stages
Glycolysis- anaerobic
Citric Acid Cycle (Krebs Cycle)- aerobic
ETC (Electron Transport Chain)- aerobic

11. Aerobic respiration -energy produced using oxygen
Anaerobic respiration - also called Fermentation - a process producing energy without oxygen

12. Fermentation
1. Lactic Acid Fermentation- when there is no oxygen, ex: muscles while running
2. Alcoholic Fermentation - yeast, bacteria, this is how we make beer, cheese, bread, vinegar, wine and cider

13. Photosynthesis vs. Respiration
Food made
Food broken down
Energy from sunlight stored in glucose
Stored energy in glucose released
CO2 taken in
CO2 and H2O given off
O2 given off
O2 taken in
Occurs in the presence of chlorophyll- plants only
Occurs in all living organisms
Light needed
No light needed
In Chloroplasts
In Mitochondria

14. Photosynthesis vs. Respiration