1. Chemical Energy & Trophs
How do different organisms obtain and use energy to survive in their environment?

2. How do Organisms get carbohydrates?
1. Autotrophs: make their own carbohydrates using inorganic compounds
Phototrophs: use the sunlight for E source
Chemotrophs: use chemicals for E source
2. Heterotrophs: eat other organisms for carbs
Describe the relationship between autotrophs and heterotrophs.

3. Cellular Energy
Cells must convert carbohydrates into a form of energy they can use.
Cells cannot directly use carbohydrates for energy
Analogy: cannot use Canadian money in the US. You have to convert it first.

4. Cellular Energy Cells use carbohydrate’s energy to make ATP
ATP (adenosine triphosphate): molecule used to carry chemical energy
Carries energy in its bonds

5. Cellular Energy
The energy from ATP can power different kinds of work in the cell.
(a) Mechanical work
(b) Transport work
(c) Chemical work
Low concentration of solute
ATP
ADP + P
ADP + P
ATP
ADP + P
ATP
Chlamydomonas
Flagella
Enzyme
Substrates
Product
High concentration of solute
Figure 4.12

6. How does ATP Release Energy?
Energy is released when the last phosphate group is removed (bond is broken).
ATP becomes ADP

7. How does ADP become ATP?
Carbohydrates and other foods consumed by the body contain energy.
When they are broken down, energy is released and is used to reattach a phosphate to ADP, turning it back into ATP.
Occurs in the mitochondria

8. ATP is like a Rechargeable Battery