1. How do we define life? Processes and characteristics of Living things Redi – Question: Where do maggots come from? - Conclusion: Louis Pasteur – Question: Where does the bacteria come from? - Conclusion: Spallanzani – Question: similar to Pasteur - Conclusion: Stanley Miller – Question: Can we create molecules of life based on conditions of early earth? - Conclusion: Bottom Line: __________________________________ Key Experiments

2. Essential Processes of Living things Metabolism: final result of all chemical reactions that keep the living alive; Includes all of the following Nutrition: taking in materials to use for energy Excretion: getting rid of the waste Respiration: converting energy in food into ATP ATP is the energy molecule all living things use Respiration uses??? Respiration produces??? Assimilation: making the food part of you Added as muscle, fat, bone, etc.

3. Regulation: all activities that help maintain an organisms homeostasis Homeostasis: a stable internal environment Examples??? Growth: either bigger cells or More cells Essential Processes Reproduction: making more of oneself to continue the species

4. All Living things also: Have a definite and limited size Have a limited life span Respond to changes Stimuli Evolve Are highly organized Are made of complex chemical substances

5. If a cell is the smallest living thing, what is it made of? Biotic: Abiotic: Examples important to us? Cells (Biotic) are made of organelles which are made of molecules which are made of atoms (all abiotic) So the abiotic is important!!

6. Interacting with the environment We can’t make more of the elements None of your atoms are ‘new’. Many elements, especially CHONPS are recycled constantly. Conveniently these are the elements we are made of!!! So a carbon in you might have once been a carbon in a giraffe from the past!

7. Natural Recycling Carbon:

8. Natural Recycling Oxygen:

9. Natural Recycling Nitrogen:

10. Natural Recycling Rocks: