Urey and Miller experiment?

Question

Im wondering could some provide me info/links on the urey and miller experiement.

I need:

reason for their experiment

result of their experiment

importance of their experiment in illustrating the nature and practice of science

contributions to hypotheses about the origin of life.

Answer 1

didi you happen to do this assignment at st philips christian college, salamander bay?? in australia??? because i have the EXACT same question in one of mine.

Answer 2

you dont happen to be in mr loz's bio class do you ?

Answer 3

you dont happen to be in mr loz's bio class do you ?

Answer 4

**Notes Gathered:**
The experiment conducted by Urey and Miller in 1952, was an experiment that encouraged hypothetical conditions thought at the time to be present in the early Earth. The experiment tested for the occurrence of chemical evolution. It also tested scientists Alexandra Oparin and J.B.S Haldane's hypothesis that conditions on the primitive Earth favored chemical reactions that synthesized organic compounds from inorganic precursors.

Miller hypothesized that a mixture of water (H2O), methane (CH4), ammonia (NH3) and hydrogen (H2), resembled the atmosphere of the early earth. The mixture was kept circulating by continuously boiling and then condensing the water.

The chemicals (water- H2O, methane- CH4, ammonia- NH3, and hydrogen- H2), were sealed inside a sterile array of glass tubes and flasks connected in a loop, with one flask half-full of liquid water and another flask containing a pair of electrodes. The liquid water was heated to induce evaporation, sparks were fired between the electrodes to stimulate lightning through the atmosphere and water vapor, and then the atmosphere was cooled again so that the water could condense and trickle back into the first flask in a continuous cycle.

After one week of continuous operation, Miller and Urey observed that 10-15% of the carbon within the system was now in the form of organic compounds. 2% of the carbon had formed amino acids that are used to make proteins in the living cells. Sugars, lipids and some building blocks for the nucleic acids were also formed.

**Reason for experiment:**
The Urey and Miller experiment was conducted to test the occurrence of chemical evolution of the Earth and the hypothesis that complex organics could be formed in an environment similar to that of early Earth. More specifically, they tested scientists Alexandra Oparin and J.B.S Haldane's hypothesis that conditions on the primitive Earth favored chemical reactions that synthesized organic compounds from inorganic precursors.

**Results for experiment:**
The conclusion of the experiment was that production of organic chemical species could be spontaneously produced from the conditions which existed millions of years ago. Urey and Miller showed that amino acids and other simple organic molecules could be synthesized naturally under primordial circumstances with lightning striking tidal pools, hence supplying building blocks with the biogenesis to begin spontaneously.

After one week of continuous operation of the experiment, Urey and Miller found 10-15% of the carbon in the system was now organic compounds, 2% of the carbon had formed amino acids, and sugar, lipids and building blocks for nucleic acids had also formed. (In 2008, a reanalysis of Urey and Miller's original experiment showed 22 amino acids rather than 5 that were created in one apparatus used.)

Urey and Miller's experiment showed that  organic compounds (e.g. Amino acids), essential to life, could easily be made under conditions which scientists believed to be present on the early Earth. These findings inspired many other experiments.



**Contribution to hypothesis of life:**
Based on this experiment, evolutionists have been able to establish that the primitive environment of Earth could have spontaneously generated amino acids, leading to the development of life.

Creationists counter that this experiment proves nothing about the formation of life on Earth, and there is no evidence that the primitive environment was the same type as created in the experiment.

If oxygen were present in the experiment, it would not have allowed for the formation of amino acids. Urey and Miller were aware of this and specifically left out oxygen. However, creationists believe oxygen could have been present from the beginning of life seeing that water is two parts hydrogen and one part oxygen, evaporation of water would place oxygen in the atmosphere.

**Validity and Reliability of experiment:**
A problem with the experiment was that the lightning strike used would have destroyed the amino acids if they were not removed from the environment they were created in. Urey and Miller knew of this and therefore included a trap to remove newly formed chemicals before each spark. On primordial Earth, this would not have been available.

While lightning storms were present in primitive Earth, they were not continuous as in the experiment, thus it has been debated that while amino acids and other organic compounds might have been formed, they would not have been formed in large amounts as shown in the experiment.

It is also believed that the early Earth's atmosphere did not contain predominantly reductant molecules.