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Origin of cellular life

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  • VIS Origin of cellular life

    Saw this lately, interesting findings

    Szostak begins his lecture with examples of the extreme environments in which life exists on Earth. He postulates that given the large number of earth-like planets orbiting sun-like stars, and the ability of microbial life to exist in a wide range of environments, it is probable that an environment that could support life exists somewhere in our galaxy. However, whether or not life does exist elsewhere, depends on the answer to the question of how difficult it is for life to arise from the chemistry of the early planets. Szostak proceeds to demonstrate that by starting with simple molecules and conditions found on the early earth, it may in fact be possible to generate a primitive, self-replicating protocell.
    [YT]watch?v=PqPGOhXoprU[/YT]

    This other one is a Tedtalk with stunning pictures of intracellular details

    Medical animator David Bolinsky presents 3 minutes of stunning animation that show the bustling life inside a cell.


    https://www.ted.com/talks/david_boli...nimates_a_cell
    Marcel

    "Evolution is a tinkerer not an engineer" F.Jacob
    "Without imperfection neither you nor I would exist" Stephen Hawking

  • #2
    Jack gives Harvard a good name. He used his Nobel Prize to actually change research directions and to do something risky.
    Ryan MB Hoffman, PhD
    Guild Certified Feldenkrais Practitioner

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    • #3
      Check out Susan Lindquist's hilarious analogy to show how proteins fold and fluctuate in the cell (link skips the first 1.3 minutes; watch to the 4 minute mark.)
      https://youtu.be/_Q0oOcZminY?t=76
      Ryan MB Hoffman, PhD
      Guild Certified Feldenkrais Practitioner

      Comment


      • #4
        NASA Ames Reproduces the Building Blocks of Life in Laboratory

        NASA Ames Reproduces the Building Blocks of Life in Laboratory

        NASA scientists studying the origin of life have reproduced uracil, cytosine, and thymine, three key components of our hereditary material, in the laboratory. They discovered that an ice sample containing pyrimidine exposed to ultraviolet radiation under space-like conditions produces these essential ingredients of life.

        Pyrimidine is a ring-shaped molecule made up of carbon and nitrogen and is the central structure for uracil, cytosine, and thymine, which are all three part of a genetic code found in ribonucleic (RNA) and deoxyribonucleic acids (DNA). RNA and DNA are central to protein synthesis, but also have many other roles.

        "We have demonstrated for the first time that we can make uracil, cytosine, and thymine, all three components of RNA and DNA, non-biologically in a laboratory under conditions found in space," said Michel Nuevo, research scientist at NASA's Ames Research Center, Moffett Field, California. "We are showing that these laboratory processes, which simulate conditions in outer space, can make several fundamental building blocks used by living organisms on Earth."

        An ice sample is deposited on a cold (approximately –440 degrees Fahrenheit) substrate in a chamber, where it is irradiated with high-energy ultraviolet (UV) photons from a hydrogen lamp. The bombarding photons break chemical bonds in the ices and break down the ice's molecules into fragments that then recombine to form new compounds, such as uracil, cytosine, and thymine.

        NASA Ames scientists have been simulating the environments found in interstellar space and the outer Solar System for years. During this time, they have studied a class of carbon-rich compounds, called polycyclic aromatic hydrocarbons (PAHs), that have been identified in meteorites, and which are the most common carbon-rich compound observed in the universe. PAHs typically are structures based on several six-carbon rings that resemble fused hexagons, or a piece of chicken wire.

        The molecule pyrimidine is found in meteorites, although scientists still do not know its origin. It may be similar to the carbon-rich PAHs, in that it may be produced in the final outbursts of dying, giant red stars, or formed in dense clouds of interstellar gas and dust.
        More : http://www.nasa.gov/content/nasa-ame...-in-laboratory

        The latest news on this subject

        Building Blocks of Life's Building Blocks Come From Starlight

        Life exists in a myriad of wondrous forms, but if you break any organism down to its most basic parts, it's all the same stuff: carbon atoms connected to hydrogen, oxygen, nitrogen and other elements. But how these fundamental substances are created in space has been a longstanding mystery.

        Now, astronomers better understand how molecules form that are necessary for building other chemicals essential for life. Thanks to data from the European Space Agency's Herschel Space Observatory, scientists have found that ultraviolet light from stars plays a key role in creating these molecules, rather than "shock" events that create turbulence, as was previously thought.

        Scientists studied the ingredients of carbon chemistry in the Orion Nebula, the closest star-forming region to Earth that forms massive stars. They mapped the amount, temperature and motions of the carbon-hydrogen molecule (CH, or “methylidyne” to chemists), the carbon-hydrogen positive ion (CH+) and their parent: the carbon ion (C+). An ion is an atom or molecule with an imbalance of protons and electrons, resulting in a net charge.

        "On Earth, the sun is the driving source of almost all the life on Earth. Now, we have learned that starlight drives the formation of chemicals that are precursors to chemicals that we need to make life," said Patrick Morris, first author of the paper and researcher at the Infrared Processing and Analysis Center at Caltech in Pasadena.

        In the early 1940s, CH and CH+ were two of the first three molecules ever discovered in interstellar space. In examining molecular clouds -- assemblies of gas and dust -- in Orion with Herschel, scientists were surprised to find that CH+ is emitting rather than absorbing light, meaning it is warmer than the background gas. The CH+ molecule needs a lot of energy to form and is extremely reactive, so it gets destroyed when it interacts with the background hydrogen in the cloud. Its warm temperature and high abundance are therefore quite mysterious.

        Why, then, is there so much CH+ in molecular clouds such as the Orion Nebula? Many studies have tried to answer this question before, but their observations were limited because few background stars were available for studying. Herschel probes an area of the electromagnetic spectrum -- the far infrared, associated with cold objects -- that no other space telescope has reached before, so it could take into account the entire Orion Nebula instead of individual stars within. The instrument they used to obtain their data, HIFI, is also extremely sensitive to the motion of the gas clouds.

        One of the leading theories about the origins of basic hydrocarbons has been that they formed in "shocks," events that create a lot of turbulence, such as exploding supernovae or young stars spitting out material. Areas of molecular clouds that have a lot of turbulence generally create shocks. Like a large wave hitting a boat, shock waves cause vibrations in material they encounter. Those vibrations can knock electrons off atoms, making them ions, which are more likely to combine. But the new study found no correlation between these shocks and CH+ in the Orion Nebula.

        Herschel data show that these CH+ molecules were more likely created by the ultraviolet emission of very young stars in the Orion Nebula, which, compared to the sun, are hotter, far more massive and emit much more ultraviolet light. When a molecule absorbs a photon of light, it becomes "excited" and has more energy to react with other particles. In the case of a hydrogen molecule, the hydrogen molecule vibrates, rotates faster or both when hit by an ultraviolet photon.
        More : https://www.somasimple.com/forums/ne...treply&t=21785

        Marcel

        "Evolution is a tinkerer not an engineer" F.Jacob
        "Without imperfection neither you nor I would exist" Stephen Hawking

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