GEOS 170A1 Lecture Notes - Lecture 18: Ribozyme, Heredity, Cell Nucleus

• School: University of Arizona
• Department: Geosciences
• Course: GEOS 170A1
• Professor: Martin Pepper

Document Summary

Start of life: formation of amino acids, amino acids - building for all life, all started around 3. 2 billion years ago - no free oxygen in the atmosphere yet - must be a plant! What"s needed for amino acids: water, spark, methane, hydrogen, ammonia, earth has water > surrounding planets, meteorites + comets = amino acids, possibly brought water and base for biology. The first cell: wave action, oils or clays in water, spontaneously form, behave like the living. Instructions for reproduction: need to replicate new cells, earliest source of heredity, before proteins - ribozyme nucleic acids (rna, gave rise to deoxyribonucleic acid (dna) Dna: interchangeable with all cells, we can now control the cell, every cell can read dna of every other cell, means all life came from a single ancestral cell! Diversity on earth: evolution provides modifications, descent with modification, natural selection as the modifier, environments shape the forms of life.