Biology 1002B Lecture Notes - Fall 2018 Lecture 2 - Transfer RNA, Phosphodiester bond, Messenger RNA
Document Summary
The earliest geological evidence of life was 4 bya** Biosignatures in geology are indirect evidence of these events. Banded iron (di erent oxidation states of iron in sedimentary rock) is indirectly evident of the rapid increase of oxygen in the atmosphere 2. 5 bya. Stromatolites are indirectly evident of microbial activity which are dated well over 3 bya. So, what do you need: abiotic synthesis, heritable information, formation of cells, metabolism. Miller urey experiment (reducing atmosphere (ch4, nh4, h2o, h2) + energy (spark discharge) created amino acids, building blocks of fatty acids, nucleotides, etc. Miller urey experiment concurred abiotic synthesis of biological molecules. Monomers not polymers created (building blocks of macromolecules - life is built on polymers) Same chemical and physical properties but from a biological point of view chiral partners can have fundamentally di erent e ects. All life has l-amino acids and d-sugars.
