Electron Microscopy and Pest Control
Posted March 5, 2001
Space Cells
In January 2001, scientists from various institutions announced at the Proceedings of the National Academy of Sciences, that they discovered how cells may have formed
– in outer space!
This group of scientists performed an experiment that duplicates conditions in deep space. They created a vacuum with extremely cold temperatures and intense radiation
and placed materials found in space in that environment. Under these conditions, the materials formed membranes similar to the membranes in cells.
All cells contain a selectively-permeable membrane that allows some substances into the cell but also acts as a protective coating to keep other substances out. The
materials, created by the scientists, self-assembled into what appeared to be soap-like bubbles. The surface of these bubbles are very similar to the membranes in human cells.
Jason Dworkin, a researcher at NASA who was involved in the study, equated the development of life in space to people building a home. "Maybe these molecules
were just the raw lumber lying around that allowed origin-of-life chemicals to move in and set up housekeeping or construct their own homes," he said.
One of the greatest leaps forward in evolution was when cellular life began. This allowed organisms to grow larger and centralize their functions. Hundreds of millions
of years ago, membrane-like substances may have fallen to Earth and "seeded" the evolution of life on this planet. The compounds that make these membranes could possibly have
been brought to Earth on a meteor or asteroid.
Many scientists think that these primitive cell membranes are essential for the building blocks of life. If this is true and primitive cells could form in space, then
it is quite possible that they seeded life elsewhere in the universe.
This announcement comes as an exciting follow-up to earlier discoveries in late 2000 that some microbes found in Earth’s upper atmosphere could have their origins
in outer space.
The scientists who performed this study plan on taking it further. They have already begun to test methods of injecting DNA and RNA, the genetic basis of life, into
these membranes. Although creating a new life form is a long way off, this recent breakthrough has only intensified the connection between space and Earth
Activity
Use the Internet links given below to learn more about cells and their structure. With your teacher’s permission, use a microscope to examine a cell and compare its
structure to the information you found in your research. Write an entry in your Science Journal explaining what you have found.
References
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