New insights into the origin of life on Earth

December 11, 2006

In an advance toward understanding the origin of life on Earth, scientists have shown that parts of the Krebs cycle can run in reverse, producing biomolecules that could jump-start life with only sunlight and a mineral present in the primordial oceans.

The Krebs cycle is a series of chemical reactions of central importance in cells — part of a metabolic pathway that changes carbohydrates, fats and proteins into carbon dioxide and water to generate energy.

Scot T. Martin and Xiang V. Zhang explain that a reverse version of the cycle, which makes enzymes and other biomolecules from carbon dioxide, has been getting attention from scientists studying the origin of life. If the reverse cycle worked on a lifeless Earth, it could have produced the fundamental biochemicals needed for the development of more-advanced biological systems like RNA that could reproduce themselves.

In a report scheduled for the Dec. 13 issue of the weekly Journal of the American Chemical Society, Martin and Zhang demonstrate that three of the five chemical reactions in the reverse Krebs cycle worked and produced biomolecules on the surface of a mineral believed to have been present in the waters of the early Earth. The mineral -- sphalerite -- acted as a photocatalyst that worked with sunlight to foster the chemical reactions.

Source: American Chemical Society

Explore further: Study reveals how shift work disrupts metabolism

Related Stories

Study reveals how shift work disrupts metabolism

July 9, 2018

Working night shifts or other nonstandard work schedules increases your risk of becoming obese and developing diabetes and other metabolic disorders, which ultimately also raises your risk of heart disease, stroke and cancer.

Molecular machine exploits motion in a single direction

June 21, 2018

Life is driven by molecular machines. Found in every cell, these tiny motors convert chemical energy into work to keep the body moving. The invention of synthetic molecular machines, which perform similar jobs to power miniaturized ...

Habitable water world exoplanets

June 29, 2018

There are currently about fifty known exoplanets whose diameters range from Mars-sized to several times the Earth's and which also reside within their stars' habitable zone – the orbital distance within which their surface ...

Recommended for you

NASA's new mini satellite will study Milky Way's halo

July 18, 2018

Astronomers keep coming up short when they survey "normal" matter, the material that makes up galaxies, stars and planets. A new NASA-sponsored CubeSat mission called HaloSat, deployed from the International Space Station ...

Splitting water: Nanoscale imaging yields key insights

July 18, 2018

In the quest to realize artificial photosynthesis to convert sunlight, water, and carbon dioxide into fuel—just as plants do—researchers need to not only identify materials to efficiently perform photoelectrochemical ...

Google braces for huge EU fine over Android

July 18, 2018

Google prepared Wednesday to be hit with huge EU fine for freezing out rivals of its Android mobile phone system in a ruling that could spark new tensions between Brussels and Washington.

Supersharp images from new VLT adaptive optics

July 18, 2018

ESO's Very Large Telescope (VLT) has achieved first light with a new adaptive optics mode called laser tomography—and has captured remarkably sharp test images of the planet Neptune and other objects. The MUSE instrument ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.