Past Events

  • 2013 Feb 07

    How can geochemistry define biochemistry?

    9:00am

    Location: 

    Biological Laboratories, 16 Divinity Ave., BL Room #1075, Cambridge, MA

    Olga Taran (Dept. of Chemistry & Chemical Biology/Whitesides Lab)

    Life on Earth is shaped by the environmental conditions of the planet. Therefore, it is probable that life started as a subcycle of geochemical cycles on early Earth. I will talk about the possible relationships between clay weathering and K+/Na+ gradients, evaporation of saline lakes and condensation reactions, in addition to the Krebs cycle and conductive minerals. I suggest that the first compartments were small rock cavities that hosted simple chemical networks formed by small organic...

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  • 2013 Jan 23

    Origins of Life Systems Chemistry

    4:00pm

    Location: 

    Geo Museum, 24 Oxford Street, Haller Hall, Rm. 102, Cambridge, MA

    John Sutherland (Medical Research Council Laboratory of Molecular Biology - Cambridge, UK) 

    The lecture will cover recent advances in systems chemistry syntheses of the informational, catalytic and compartment–forming molecules thought necessary for the emergence of life.

  • 2012 Dec 19

    Do cells know physics? From universal cellular micromechanics to peculiar walking strategies

    4:00pm

    Location: 

    Geo Museum, 24 Oxford Street, Haller Hall, Rm. 102, Cambridge, MA

    Bartosz Grzybowski (Northwestern University - Dept. of Chemical & Biological Engineering) 

    One of the greatest mysteries of life is how a collection of molecules enclosed by a molecular sac self-organizes into a complex system capable of maintaining structural integrity, sensing the environment, propelling itself, self-replicating, and more. In my talk I will illustrate how a combination of cell biology and physics can offer some unique insights into the static organization and dynamic behaviors of cells. Accordingly, the talk will...

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  • 2012 Dec 06

    Evolution of the Genetic code and the Ribosome

    9:00am

    Location: 

    Biological Laboratories, 16 Divinity Ave., BL Room #1075, Cambridge, MA

    Hyman Hartman (MIT-Dept. of Earth, Atmospheric & Planetary Sciences)

    Messenger RNA is translated into Protein by the translational machinery of the cell, which includes twenty enzymes that attach the twenty amino acids to the transfer RNAs (tRNAs) with the correct anticodon. These enzymes are aptly called the Aminoacyl-tRNA synthetases. The machinery also includes the initiation and elongation factors and then there is the Ribosome, which is composed of a large subunit (LSU) and a small subunit (SSU). The ribosome has been crystallized and its three...

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  • 2012 Nov 28

    Cell wall deficient (L-form) bacteria: mechanism of proliferation and implications for the emergence of cellular life

    4:00pm

    Location: 

    Geo Museum, 24 Oxford Street, Haller Hall, Rm. 102, Cambridge, MA

    Jeff Errington (Newcastle University - Centre for Bacterial Cell Biology) 

    The cell wall is a defining structure of bacterial cells. It provides a protective outer shell and is crucial in pathogenesis as well as the target for important antibiotics. Synthesis of the wall is organised by cytoskeletal proteins homologous to tubulin (FtsZ) and actin (MreB). Because all major branches of the bacterial lineage possess both wall and cytoskeleton, these were probably present in the last common ancestor of the bacteria. L-forms are unusual...

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  • 2012 Nov 01

    An early reducing atmosphere inferred from mantle noble gases

    9:00am

    Location: 

    Biological Laboratories, 16 Divinity Ave., BL Room #1075, Cambridge, MA

    Sujoy Mukhopadhyay (Dept. of Earth & Planetary Sciences)

    The composition of the Earth’s early atmosphere is of great importance in understanding the nature of chemical reactions occurring on our planet’s surface. For example, an early reducing atmosphere has been shown to be significantly more conducive to prebiotic chemistry than an oxidized H2O-CO2 atmosphere. The composition of the earliest atmosphere is, however, a strong function of whether atmospheric gases were liberated from the Earth’s mantle or delivered via late accreting chondritic planetesimals that...

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  • 2012 Oct 17

    How to Identify an Inhabited Exoplanet

    4:00pm

    Location: 

    Geo Museum, 24 Oxford Street, Haller Hall, Rm. 102, Cambridge, MA

    Sara Seager (MIT - Dept. of Earth, Atmospheric & Planetary Sciences)

    Biosignature gases are gases emitted by life that can accumulate in an exoplanet atmosphere to remotely detectable levels by future space telescopes. Until now, the dominant focus has been on Earth-like planets, because Earth is the only known planet with life. Yet exoplanets are astonishingly diverse—in terms of their masses, densities, orbits, and host star types—and this diversity motivates a radical extension of what conventionally constitutes a habitable planet. By building a general...

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  • 2012 Oct 04

    A New Model for the Origin of the Earth and Moon

    9:00am

    Location: 

    Biological Laboratories, 16 Divinity Ave., BL Room #1075, Cambridge, MA

    Sarah Stewart (Dept. of Earth & Planetary Sciences)

    In the standard model for planet formation, Earth accreted via a series of giant impacts and the terminal giant impact produced the Moon and fully melted the Earth. The Moon and Earth are identical in multiple isotope systems that show significant variations between most meteorite groups and planetary bodies. Thus, the simplest explanation for the isotopic similarity is that the Moon and Earth’s mantle have a common origin. In contrast, canonical giant impact simulations find that the lunar disk is...

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  • 2012 Sep 26

    Microbial sulfate reduction as a vehicle for reconstructing Earth's ancient oxygen budgets

    4:00pm

    Location: 

    Geo Museum, 24 Oxford Street, Haller Hall, Rm. 102, Cambridge, MA

    David Johnston (Harvard University - Dept. of Earth & Planetary Sciences)

    The story of Earth’s biological and chemical evolution is locked within the geological record of marine sediments, and deciphering these stories requires a means of accessing and calibrating that information. Of the directly targetable marine sedimentary records, the stable isotopes of sulfur are one of the most powerful tools for paleo-environmental reconstructions. This applicability is rooted in the quantitative linkage to surface oxygen budgets (namely atmospheric O2) and inherent...

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