1. Bellringer 11/17 1. What is energy?
2. What do the following have in common?
Reminders: HW Sec 9.1 vocabulary, pay lab fee

2. Photosynthesis and Respiration
Energy in the Cell
Photosynthesis and Respiration

3. Energy Energy- the ability to do work
The energy for living things is stored in chemical compounds
2 organelles are responsible for making those compounds for cells:
Chloroplasts- through photosynthesis in plants
Mitochondria- through cellular respiration in animals

4. Where Does the Energy Come From?
Energy is stored in food!!!
Plants use sunlight to make their food.
Plants are autotrophs (producers)—they make their own food.
Animals and other organisms that cannot use the sun’s energy directly must consume food for energy.
Animals are called heterotrophs (consumers)—they cannot make their own food.

5. Chemical Energy Energy in food is stored in chemical bonds
Food must be digested (broken down) before this energy can be used
There are 3 main energy molecules that cells use:
ATP (adenosine triphosphate)
ADP (adenosine diphosphate)
Glucose (C6H12O6)- carbohydrates

6. ATP and ADP ATP is made of: ADP is made of:
Adenine (a nitrogen compound)
5-carbon sugar
3 phosphate groups
ADP is made of:
2 phosphate groups
So what’s the only difference between the two?
The phosphate groups! 2 vs. 3

7. The ATP – ADP Cycle

8. ATP vs. ADP
ATP can become ADP by breaking a chemical bond and removing a phosphate group
When you break chemical bonds you RELEASE energy
The cell can store energy by ADDING a phosphate group to ADP to become ATP.
ATP acts like a fully charged battery

9. ATP vs. Glucose
ATP is NOT good for storing large amounts of energy long-term.
The cell uses glucose because it can store 90 times as much energy as ATP.

10. Photosynthesis Photo: using light Synthesis: to put something together
>>>The process in which cell use light energy to make carbohydrates (food)
Reminder: takes place in chloroplasts
Chlorophyll- pigment that traps light energy needed for photosynthesis (found in chloroplasts)

11. Basic Photosynthesis
Plants absorb carbon dioxide from the air, pull water up through their roots and use light to make sugar. Plants use the sugar to grow. Plants give off oxygen as a by-product. The green parts of the plant makes the sugar and oxygen. Carbon dioxide + water + sunlight = sugar + oxygen 

12. Photosynthesis Summarized
__ CO2 + __ H2O + light energy = __C6H12O6 + __O2
trapped by chlorophyll
But, we need to balance this equation…
So….
6 CO2 + 6 H2O + light energy = C6H12O6 + 6 O2
This process contains light-dependent (requires sunlight) and light-independent reactions (no light needed)
Can we guess which part is which?

13. Cellular Respiration The opposite of photosynthesis
Instead of making food, we now break down that food to release energy
Reminder: takes place in the mitochondria
C6H12O O2 = 6 CO2 + 6 H2O + ATP
(from plants) (for plants) (for our use)

14. Cellular Respiration Stages
Glycolysis- takes place in the cytoplasm of the cell
Citric Acid Cycle (Krebs Cycle)- in the mitochondria
ETC (Electron Transport Chain)- in the inner membrane of the mitochondria
To remember:
Glycolysis: anaerobic (no oxygen needed)
Citric Acid Cycle and ETC: aerobic (need oxygen to go)
Total energy after Cellular Respiration: 38 ATP

15. Cellular Respiration

16. What happens w/o O? 2 kinds of Fermentation:
When the cell needs energy (when you exercise heavily or run long-distance), but little or no O is available for proper respiration, the cell will enter an anaerobic process call fermentation
2 kinds of Fermentation:
Lactic Acid- this is why muscles hurt
Alcoholic - used by yeast, bacteria, this is how we make beer, cheese, bread, vinegar, wine and cider

17. Photosynthesis vs. Respiration

18. 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

19. The ATP – ADP Cycle

20. Basic Photosynthesis
Plants absorb carbon dioxide from the air, pull water up through their roots and use light to make sugar. Plants use the sugar to grow. Plants give off oxygen as a by-product. The green parts of the plant makes the sugar and oxygen. Carbon dioxide + water + sunlight = sugar + oxygen