Tag Archives: cellular structure

New Study Outlines ‘Water World’ Theory of Life’s Origins

Life took root more than four billion years ago on our nascent Earth, a wetter and harsher place than now, bathed in sizzling ultraviolet rays. What started out as simple cells ultimately transformed into slime molds, frogs, elephants, humans and the rest of our planet’s living kingdoms. How did it all begin?

A new study from researchers at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., and the Icy Worlds team at NASA’s Astrobiology Institute, based at NASA’s Ames Research Center in Moffett Field, Calif., describes how electrical energy naturally produced at the sea floor might have given rise to life. While the scientists had already proposed this hypothesis — called “submarine alkaline hydrothermal emergence of life” — the new report assembles decades of field, laboratory and theoretical research into a grand, unified picture. (more…)

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Yale Study: How Mitochondrial DNA Defects Cause Inherited Deafness

Yale scientists have discovered the molecular pathway by which maternally inherited deafness appears to occur: Mitochondrial DNA mutations trigger a signaling cascade, resulting in programmed cell death. The study is in the Feb. 17 issue of Cell.

Mitochondria are cellular structures that function as “cellular power plants” because they generate most of the cell’s supply of energy. They contain DNA inherited from one’s mother. Mitochondria determine whether a cell lives or dies via the process of programmed cell death, or apoptosis. (more…)

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