Lecture 02 Flashcards
word for “the study of the universe”
cosmology
5 steps of big bang theory
quark form proton and neutron=1H & 4He
expansion, condensation, formation of protostars
protostars burn producing heavier elements
protostar explode& produce supernova超新星
solar system form
3 steps of origin of solar system
fragmentation of an interstellar cloud
contraction& flattening of the solar nebula
condensation of nebular material
5 unique conditions of Earth
sun energy
stable climate due to CO2& ozone
composition of element
liquid water
iron core(magnetic field, keep things from hitting the earth )
what is 4.6 bya & how determine
earth formed
stone from moon 4.5 bya, the stones are from earth, earth form at least 4.6 bya
4.2-4.1 bya & how determine
crust form
zircon crystal, require liquid H2O& low T
3 ways to determine dates
zircon
looking at layer- relative
half life& radioactive
7 prerequisite for origin of molecules
sun: steady radiant energy
earth orbit is nearly circular, steady distance from sun
chemically diverse
C is structural basis of life
H2O universal solvent
Stanley Miller在1953重演formation of organic molecule的实验
名字，条件，结果
prebiotic soup
条件
electric spark& constituent of primitive atm
结果
17 of 20 AA, all purine& pyrimidine
3 possible sites
hydrothermal vents
volcano
clay
word for “organic molecule brought to Earth from space”
panspermia
3 个from elsewhere的例子
Murchison meteorite
(carbonaceous chondrite)
ALH84001
(microorganism on Mars)
organic molecules in interstellar space
更倾向于terrestrial origin的原因carbonaceous meteorites chiral it’s is different
carbonaceous meteorites chiral it’s is different
更倾向于RNA world的原因
Thomas Cech& Sidney Altman发现了first ribozyme
crepe model
purine/ pyrimidine bind to clay surface, made backbone of RNA
