Please take out Breeding Bunnies Lab to turn in Take out a half sheet of paper for a warm up Have your notebook turned to page 106 for the notes for today: Origin of Life

Brain Checkpoint 1. How many lobes are in the Cerebrum 2. What are the three major parts of the brain 3. What lobe is structure C? A B C

Origin of Life Page 106 Just write the red lettering into your notebook.

Origin of the Earth Universe formed 15 billion years ago (Big Bang) Galaxies formed from stars, dust and gas Earth formed 4.6 billion years ago

Origin of the Atmosphere Suns energy stripped away 1st atmosphere 2nd atmosphere formed from volcanic outgassing Primitive atmosphere: Mostly CO2, water vapor, No Oxygen, very hot, lots of lightening lesser amounts of CO, N2, H2, HCl, and traces of NH3 and CH4 (3.5 bya)

Formation of Earth’s Oceans Oceans formed from off gassing of water vapor from volcanoes and meteorites with ice. Condensation Rain Early in Earth’s history, widespread volcanic activity released large amounts of water vapor (H2O vapor) and smaller quantities of other gases. As Earth cooled, the water vapor (a) condensed into clouds and (b) fell to Earth’s surface, where it accumulated to form the oceans (c).

Origin of the Atmosphere O2 came in 1.5 bya from photosynthesis Present atmosphere: 78% N2, 21% O2, 0.04% CO2, + trace gasses

Origin of Life Miller & Urey (1953)- Organic Molecule Theory - mixed water vapor, NH3, CH4, H2+ electric spark amino acids and other organic compounds electrodes spark CH4 NH3 H2 water vapor condenser boiling water water containing organic compounds

Origin of Life Produced: 20 amino acids Several sugars Lipids Purine and pyrimidine bases (found in DNA, RNA & ATP)

Origin of Life Life began~ 3.5 bya Organic molecules (C H O N P S) swimming in shallow seas Stage 1: Abiotic synthesis of organic molecules such as proteins, amino acids and nucleotides

Origin of Life Stage 2: joining of small molecules (monomers) into large molecules

Origin of Life Stage 3: origin of self-replicating molecules that eventually made inheritance possible

Origin of Life Stage 4: packaging these molecules into pre-cells, droplets of molecules with membranes that maintained an internal chemistry

Hydrothermal Vent Theory At the bottom of the ocean, chimneys of very hot material under immense pressure combined to make inorganic material that then formed into macromolecules and then life.

Meteorite Theory – Rocks containing bacteria and other organic molecules survived impact and seeded the planet with life.

Endosymbiotic Theory Endo= inside Symbiotic=mutually beneficial Idea that mitochondria and chloroplasts came from engulfing prokaryotic cells