History of Life Chapter 14 sections 2 and 3 (test will also include 1)

Big Bang Condensed matter exploded into basic particles Matter cooled and began to coalesce

Earth and Other Planets Gravity pulled in more debris to form solar systems Planets were further shaped Earth formed about 4.6 bya Excessive rain produced oceans 4 bya

Radiometric Dating Review – mass number, isotopes Method to determine age of mineral samples Comparison between the level of radioactive isotopes to a known level of stable isotope Measured by the time it takes to convert half of the radioactive isotopes to a stable state

Early Organic Compounds Early atmosphere was thought to have ammonia, hydrogen, water, methane Oparin – with energy added to catalyze, these compounds would react to form… ?

Basic Life Molecules Miller-Urey

Different Theories Miller-Urey simulated primordial soup model – many of those early atmosphere molecules may not have existed Bubble Model – rxns that were thought to have occurred in the atmosphere occurred inside of protected bubbles Beyond Earth – basic organic compounds came from meteors

Pre-cells  Cells Under the extreme conditions of early earth, macromolecules form spheres NOT cells yet because they do not have hereditary material – RNA can store information and act as an enzyme Earliest competition – who can replicate the most? Who can break down the most?

Early Cell Development FIRST CELL was extremely basic in structure and function – Increasing competition as resources dwindled CHEMOSYNTHESIZERS PHOTOSYNTHESIZERS – cyanobacteria  Consider changes and competition amongst the population of earth!

Adjusting to New Conditions Oxygen is now in the atmosphere! O wow. – Damage – Ozone layer – Aerobic respiration

Eukaryotes Contain membrane-bound organelles Small aerobic prokaryote was engulfed by a large anaerobic prokaryote = mitochondria Small photosynthetic prokaryote engulfed = chloroplast Evidence = membranes, DNA