1. Photosynthesis and Cellular Respiration
Chapter 5
Photosynthesis and Cellular Respiration

2. Energy in Living Systems
Section 1
Energy in Living Systems

3. Building Molecules that Store Energy
Photosynthesis – the process by which light energy is converted to chemical energy.
Autotrophs – organisms that use energy from sunlight or from chemical bonds in inorganic substances to make organic compounds.

4. Breaking Down Food for Energy
Heterotrophs – organisms that must get energy from food instead of directly from sunlight.
Get energy from food through cellular respiration.
Cellular Respiration – a metabolic process similar to burning fuel.
Releases much of the energy in food to make ATP (Adenosine Triphosphate) – ATP provides cells with energy they need to carry out the activities of life.

5. Flow of Energy Plants convert light energy to chemical energy.
Zebras get energy by eating the plants.
Lions get energy by eating the Zebras.

6. Transfer of Energy to ATP
We can write the chemical reaction for the formation of ATP as:
a) in chemicalese: ADP + Pi + energy ----> ATP
b) in English: Adenosine diphosphate + inorganic Phosphate + energy produces Adenosine Triphosphate
The chemical formula for the expenditure/release of ATP energy can be written as:
a) in chemicalese: ATP ----> ADP + energy + Pi
b) in English Adenosine Triphosphate produces Adenosine diphosphate + energy + inorganic Phosphate

7. ATP

8. Quiz
Organisms that can make their own food using the energy of the sun are called ______________.
Organisms that obtain their energy by eating other organisms are called ______________.
What is the primary source of energy that flows through most living systems?
What is the difference between ATP and ADP?
Illustrate the flow of energy from the Sun to Self-feeders to Herbivores (plant eaters) to Carnivores (meat eaters).

9. Activity
Trace the energy in a Ham and Cheese Sandwich back to the Sun.
* Use words and illustrations.
* Be creative.
Trace the following items of the sandwich:
1. Ham
2. Cheese
3. Bread