1. Cellular Energy
Chapter 8

2. 8.1 How Organisms Obtain Energy
All living organisms use energy to carry out all biological processes.

3. Energy Nearly all the energy on this planet comes from the sun
Winds (hurricanes and tornadoes) are powered by the sun.
Rivers (and waterfalls) are powered by the sun (getting the water to higher ground as rain).
Plants (and indirectly animals) are powered by the sun.
Fossil fuels (coal, oil & natural gas) are remains of dead plants and animals

4. How do we get energy? EATING!
OUR BODIES BREAK DOWN THE FOOD WE EAT SO WE CAN GET ENERGY

5. Transformation of Energy
Energy: The ability to do work
In our cells, energy is stored in the form of ATP…

6. ATP ATP = Adenosine Triphosphate
1 large molecule that is made of 5 smaller molecules bonded together
Adenine, ribose, and 3 phosphate groups

7. ATP
ATP breaks apart and releases its energy to cells
ENERGY!!!

8. ATP
When is breaks apart, it releases energy and loses a phosphate group, now it is called ADP

9. Then what?
ATP breaks apart and creates energy and ADP…then what happens?
It is recharged! It uses energy and gains and extra P is becomes ATP again

10. ADP  ATP ADP ATP Adenosine diphosphate (ADP) + Phosphate
Energy
Energy
Adenosine diphosphate (ADP) + Phosphate
Adenosine triphosphate (ATP)
Partially
charged
battery
Fully
charged
battery
ADP  ATP

11. How do the things we eat get energy?

12. Autotrophs & Heterotrophs
Autotrophs – organisms that make their own energy for food
Heterotrophs – organisms that need to ingest food to obtain energy

13. Energy
Plants use energy from the sun to grow and make their own energy
HOW DO THEY DO THIS?

14. 8.2 Photosynthesis
Light energy is trapped and converted into chemical energy during photosynthesis

15. Photosynthesis “Photo”– light “Synthesis” – putting together
Process of plants making their own food by combining carbon dioxide and water to form sugar and oxygen in the chloroplasts
Requires energy form the sun to happen
The process is cyclical, the products from one reaction are the reactants for the next reaction

16. The food produced is glucose (a simple sugar) and oxygen (which we like!)

17. carbon + water  glucose + oxygen dioxide

18. Which part of the plant do you think photosynthesis happens in?

19. Chloroplast Chloroplasts!
Inside each chloroplast is where the photosynthesis reaction takes place.

20. Chlorophyll
Chlorophyll - the main pigment found in the chloroplasts responsible for photosynthesis, they have the ability to absorb energy from sunlight
A pigment is a colored chemical (like a dye), chlorophyll gives most leaves their green color
Different chlorophylls absorb different wavelengths of light

21. Photosynthesis
There are two parts, light independent, and light dependent
Light dependent takes place in the light
Light independent takes place in the dark

22. Phase 1: Light Reactions
The “photo” part
The light is captured by chloroplasts and turned into chemical energy (ATP)

24. Phase 2: The Calvin Cycle
CARBON DIOXIDE
ATP
In the second phase, called the Calvin cycle, carbon dioxide is used to make sugar (glucose)
The “synthesis” part
Light independent
CALVIN CYCLE
GLUCOSE

25. Chloroplast H2O CO2 Light Light Reactions Calvin Cycle ATP
Sugar (Glucose) O2

26. 8.2 Cellular Respiration
Living organisms obtain energy by breaking down organic molecules during cellular respiration.

27. So…
How do our bodies take food and make it into energy?

28. Cellular Respiration!
Cellular respiration: is a chemical process in which glucose molecules are broken down to release energy (ATP) for cellular functions
Occurs in all living cells
Cellular respiration is the opposite of photosynthesis
Completed in the mitochondria
The products of photosynthesis – oxygen & glucose – are the reactants needed for cellular respiration, and the products of cellular respiration – carbon dioxide & water – are the reactants for photosynthesis

29. What happens to the food we eat?
1. We break our food down into small molecules
2. We use the energy stored in the bonds in our food to make ATP
3. A small amount of the food becomes waste

30. Like photosynthesis, cellular respiration has a specific chemical reaction that happens every time.+ 
We breathe out carbon dioxide
We breathe in oxygen and get glucose from our food
C6H12O O  H2O CO Energy
glucose oxygen water carbon dioxide (ATP)

31. Cellular Respiration
This process is the reverse of photosynthesis.

32. Cellular Respiration Anaerobic Aerobic Does NOT need oxygen
Happens in cytoplasm of cell
Fermentation
Requires oxygen
Happens in mitochondria
Cellular Respiration

34. Fermentation Lactic Acid Alcohol
This is done by your muscles when the demand for ATP is high, but you are low in oxygen. (while working out) This can cause soreness in the muscles
sugar breaks down into carbon dioxide and ethanol
The carbon dioxide produced in this manner can be used to allow bread to rise