In 1953, Harold Urey and Stanley Miller carried out an amazing experiment in which they produced "molecules of life" from a mixture of gases that they proposed existed in a primordial earth. The experiments simulated what would happen when lightning strikes provided energy for chemical reactions in the atmosphere and suggested a hypothesis for how life might have developed on our planet. Amino acids were the vital molecules that formed in this experiment and supported this hypothesis for the origin of life.

An amino acid is a molecule that contains two functional groups, an amine and a carboxylic acid, as shown in Figure 1. In this illustration there is an additional group called the side chain, designated with an R. The variation seen in naturally occurring amino acids arises from differences in this side chain. The twenty naturally occurring molecules are listed in Table 1. In an aqueous solution, this structure may change so that a proton from the COOH transfers to the NH2 and a zwitterion is formed. This structure depends on the pH of the solution. Most physiological systems fall into such a pH range so the zwitterion form of amino acids is the most stable form in the human body.

Yeah, this is great information regarding to importance of amino acid.This is not only lovable but it also supplies some goods facts related to amino acid.

Hi chenhongxia,

"from a mixture of gases that they proposed existed in a primordial earth. The experiments simulated what would happen when lightning strikes provided energy for chemical reactions in the atmosphere and suggested a hypothesis for how life might have developed on our planet. Amino acids were the vital molecules that formed in this experiment and supported this hypothesis for the origin of life."

Does it say in that paper your reading from what their evidence was to suggest those gases actually existed at that particular time, where they came from and how they were stored? Grasses, trees, water ( which probably came from crumbling mountains) all arrived after, not sure when water arrived on the planet. Going back a bit further to the big bang must have been a phenomenal piece of study. Do you get all of your information from LookChem?

Cheers

You have yourself a bit mixed up mate.
All protein is made up of amino acids. They link up next to each other,
hundreds of them, to make one protein.
There are lots of kinds of amino acids and most of the time our pody
can change the ones we eat and make them into the ones we need for
growth and maintainance.
But there are 9 amino acids that the body cant make and so you have
to make sure you get a balance of all of these "essential amino acids".
This doesnt present much of a problem because good quality protein
sources such as fish, meat and eggs come with all nine.

Hi Willson,
If life actually came about in the manner proposed by the researchers then it would require building blocks to proceed to the next step, amino acids look to be the most likely candidates proposed so far.Gradually they would have become "organised" to form proteins, anyway it was a good experiment here it is . The experiment was about the beginning not the present.

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Miller-Urey experiment
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The experiment
The experiment

The Miller-Urey experiment (or Urey-Miller experiment) was an experiment that simulated hypothetical conditions present on the early Earth and tested for the occurrence of chemical evolution. Specifically, the experiment tested Oparin and Haldane's hypothesis that conditions on the primitive Earth favored chemical reactions that synthesized organic compounds from inorganic precursors. Considered to be the classic experiment on the origin of life, it was conducted in 1953 by Stanley L. Miller and Harold C. Urey at the University of Chicago.[1][2][3]
Contents
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* 1 Experiment and interpretation
* 2 Other experiments
* 3 Earth's early atmosphere
* 4 Recent related studies
* 5 See also
* 6 References
* 7 External links

[edit] Experiment and interpretation
The Miller-Urey experiment attempts to recreate the chemical conditions of the primitive Earth in the laboratory, and synthesized some of the building blocks of life.
The Miller-Urey experiment attempts to recreate the chemical conditions of the primitive Earth in the laboratory, and synthesized some of the building blocks of life.

The experiment used water (H2O), methane (CH4), ammonia (NH3) and hydrogen (H2). The chemicals were all sealed inside a sterile array of glass tubes and flasks connected together 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 simulate 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.

At the end of one week of continuous operation Miller and Urey observed that as much as 10-15% of the carbon within the system was now in the form of organic compounds. Two percent of the carbon had formed amino acids, including 2-3 of the 22 that are used to make proteins in living cells, with glycine as the most abundant. Sugars, lipids, and some of the building blocks for nucleic acids were also formed. Nucleic acids (DNA, RNA) themselves were not formed. As observed in all consequent experiments, both left-handed (L) and right-handed (D) optical isomers were created in a racemic mixture. Virtually all amino acids in the proteins of living cells are left-handed amino acids. Any right-handed amino acids, for the most part, are poisonous to the construction of the protein, causing it to unravel. Equal amounts of left- and right-handed amino acids would not be an environment friendly to life

Cheers