1. Origin of Life

2. The Earth was around for 1 billion years before we see signs of LIFE…. So…where did it come from?

3. Most Likely SCIENTIFIC explanation… figure 27.7 Origin of the 1 st cell figure 27.7 Origin of the 1 st cell

4. Primitive Earth Volcanoes Erupting! Meteors Bombarding! Volcanoes Erupting! Meteors Bombarding! Primordial Soup: Primordial Soup: Rain washed atmospheric molecules into the ocean making “the soup” Rain washed atmospheric molecules into the ocean making “the soup” What molecules were in the early Earth’s atmosphere? What molecules were in the early Earth’s atmosphere?

5. INORGANIC CHEMICALS Nitrogen Nitrogen Methane (CH4) Methane (CH4) Ammonia(NH3) Ammonia(NH3) Hydrogen (H) Hydrogen (H) NOTE: NOTE: NO OXYGEN!!! NO OXYGEN!!! These inorganic molecules gave rise to… These inorganic molecules gave rise to…

6. SMALL ORGANIC MOLECULES Miller-Urey Experiment- p 547 ORGANIC MACROMOLECULES RNA first? Protein first? Both? RNA first? Protein first? Both? Just know that these molecules combined to form… Just know that these molecules combined to form…

7. PLASMA MEMBRANE Lipids and Proteins came together spontaneously FIRST PROTOCELL Had a lipid protein membrane and could carry on Energy Metabolism

8. CELLS! Probably Heterotrophs at first= takes in preformed food Probably Heterotrophs at first= takes in preformed food Led to Autotrophs = make own food Led to Autotrophs = make own food Chemoautotrophs Chemoautotrophs Photoautotrophs Photoautotrophs What impact would this have on the Earth?

9. BUT… We don’t have good scientific evidence for how the first cell came to be… We don’t have good scientific evidence for how the first cell came to be… What do you think???? What do you think????

10. How did life originate? Spontaneous Generation Spontaneous Generation Idea that nonliving material can produce life Idea that nonliving material can produce life Can you give me an example of what Aristotle was seeing? Can you give me an example of what Aristotle was seeing?

11. Spontaneous Generation Francesco Redi was the first to disprove this idea. Francesco Redi was the first to disprove this idea. How do you think he did it? How do you think he did it?

12. Spontaneous Generation Louis Pasteur went on to disprove it as well. Louis Pasteur went on to disprove it as well.

13. So where did life come from??? Before life can begin, what molecules would we need to make??? Before life can begin, what molecules would we need to make??? CO2 CO2 O2 O2 Nucleic Acids Nucleic Acids Proteins Proteins Glucose Glucose ATP ATP

14. So which came first??? You can’t have proteins without life, but you can’t have life without proteins… So what the heck?!?! You can’t have proteins without life, but you can’t have life without proteins… So what the heck?!?!

15. Early Earth Landscape

16. How about some more modern ideas Maybe Meteorites Maybe Meteorites

17. Meteorites What must have been carried on the meteorite? What must have been carried on the meteorite?

18. Another theory… Earth’s atmosphere was probably made up of gases that contained organic elements. Earth’s atmosphere was probably made up of gases that contained organic elements. What are they?? What are they?? CO2 CO2 CH4… CH4…

19. Primordial Soup Hypothesis Primordial Soup: Primordial Soup: The mix of atmospheric molecules and water The mix of atmospheric molecules and water Rain washed atmospheric molecules into the ocean making “the soup” Rain washed atmospheric molecules into the ocean making “the soup” What molecules were in the early Earth’s atmosphere? What molecules were in the early Earth’s atmosphere?

20. Primordial Soup

21. Primordial Soup Theory Energy fueled chemical reactions among these gases which combined them into organic compounds. Energy fueled chemical reactions among these gases which combined them into organic compounds.

22. Chemical Evolution Harold Urey and Stanley Miller provided evidence to support this. Harold Urey and Stanley Miller provided evidence to support this.

23. Chemical Evolution

24. Miller Urey Simulation http://bcs.whfreeman.com/thelifewire/content /chp03/0302001.html http://bcs.whfreeman.com/thelifewire/content /chp03/0302001.html http://bcs.whfreeman.com/thelifewire/content /chp03/0302001.html http://bcs.whfreeman.com/thelifewire/content /chp03/0302001.html

25. The Earth was around for 1 billion years before we see signs of LIFE…. So…where did it come from?

26. INORGANIC CHEMICALS Nitrogen Nitrogen Methane (CH4) Methane (CH4) Ammonia(NH3) Ammonia(NH3) Hydrogen (H) Hydrogen (H) NOTE: NOTE: NO OXYGEN!!! NO OXYGEN!!! These inorganic molecules gave rise to… These inorganic molecules gave rise to…

27. SMALL ORGANIC MOLECULES Miller-Urey Experiment- p 547 ORGANIC MACROMOLECULES RNA first? Protein first? Both? RNA first? Protein first? Both? Just know that these molecules combined to form… Just know that these molecules combined to form…

28. PLASMA MEMBRANE Lipids and Proteins came together spontaneously FIRST PROTOCELL Had a lipid protein membrane and could carry on Energy Metabolism

29. CELLS! Probably Heterotrophs at first= takes in preformed food Probably Heterotrophs at first= takes in preformed food Led to Autotrophs = make own food Led to Autotrophs = make own food Chemoautotrophs Chemoautotrophs Photoautotrophs Photoautotrophs What impact would this have on the Earth?

30. TP Time!