A2.1 Origins of Cells Flashcards
Pre-Biotic Formation of Carbon Compounds
Volcanic eruptions, lightnings was a regular occurrence.
Early gaseous compounds may have included methane, ammonia, and carbon dioxide
Earth’s early atmospheric components coupled with high surface temperature and lightning, followed by a gradual cooling, resulted in spontaneous formation of many carbon compounds.
Abiogenesis
Abiogenesis: the theory that living cells arose from non-living matter
explain abiogenesis
There wasnon-living synthesis ofsimple organic molecules
These simple organic molecules became assembled intomore complex polymers
These molecules becamepackaged into membraneswith an internal chemistry different from their surroundings (compartmentalization)
Certain polymers formed the capacity toself-replicate(enabling inheritance)
Miller-Urey Experiment
In 1953, Stanley Miller and Harold Urey conducted an experiment to simulate the condition thought to be present on early Earth.
Aim: demonstrate non-living synthesis of simple organic molecules
results of the miller-urey experiment
Miller identified several simple organic molecules including hydrocarbons and amino acids.
miller-urey experiment (1)
The postulated conditions of pre-biotic Earth was recreated using a closed system of flasks and tubes
miller-urey experiment (2)
Water was boiled to vapour to reflect thehigh temperaturescommon to Earth’s original conditions
miller-urey experiment (3)
The vapour was mixed with a variety of gases (including H2, CH4, NH3) to create areducing atmosphere(nooxygen)
miller-urey experiment (4)
This mixture was then exposed to anelectrical discharge(simulating the effects of lightning as an energy source for reactions)
miller-urey experiment (5)
The mixture was then allowed tocool (concentrating components) and left for a week
miller-urey experiment (6)
After this time, the condensed mixture was analysed and found to contain traces of simple organic molecules
