Credit: Happy Little Nomad/Wikimedia Commons
Gimme an F
Chlorophyll, the pigment that makes the world go ’round, has come in four known flavors for more than 60 years: chlorophylls a, b, c and d. Now scientists have discovered another version of the pigment that allows plants and other photosynthesizing organisms to harness sunlight for making food and oxygen. Dubbed chlorophyll f, the new version is found in extracts of ground-up stromatolites — knobby chunks of rock and algae — collected in western Australia’s Shark Bay (SN: 9/11/10, p. 13).
Chlorophyll f absorbs light most efficiently at a wavelength around 706 nanometers, just beyond the red end of the visible spectrum. The previously known chlorophylls absorb light of shorter wavelengths. Exploiting slightly longer wavelengths may allow the microorganism that makes chlorophyll f (a filamentous cyanobacterium, scientists think) to survive in shady habitats, beneath creatures that snatch up the other usable wavelengths. A chemical extra known as a formyl group on one of the chlorophyll’s carbons appears to set chlorophyll f apart from its kin, says study leader Min Chen of the University of Sydney in Australia. “This very small modification of the pigment happens,” Chen says, “then the organism can use this unique light.”
Opiates for the masses Researchers unravel the final steps in the opium poppy’s production of morphine, which could mean cheaper painkillers (SN: 4/10/10, p. 5).
See the heat The protein that makes wasabi feel fiery also lets snakes “see” heat radiating from their prey (SN Online: 3/14/10).
Howdunit Figuring out how chemical warfare agents such as mustard gas were made may help identify their maker (SN Online: 3/23/10).
Aluminum foils water Tiny clusters of aluminum atoms can extract pure hydrogen from water, which may aid the production of hydrogen-based fuels (SN Online: 3/4/10).
Presto chango! Researchers watch as energy-producing photosynthetic complexes self-assemble (final product, above), a possible first step to self-repairing solar cells (SN: 10/9/10, p. 14).
Life’s cold start RNA, the molecule of heredity that may have kicked off life on Earth, can begin to replicate within tiny liquid pockets in ice, suggesting life didn’t need a warm cocoon (SN: 10/23/10, p. 11).
Dark and delicious Compared with lighter roasts, dark-roasted coffees have higher levels of a compound that helps dial down production of stomach acid (SN: 4/24/10, p. 13).
Scent of fear A compound that prompts aggression makes mice freeze with fear when they smell the molecule coming from a rat or cat (SN: 6/5/10, p. 14).
Dietary toxin A newly described microbe may substitute arsenic for phosphorus, a basic ingredient of life, raising questions about the limits of biochemistry (SN: 1/1/11, p. 5).
Tiny tools Enzyme-based machinery could have medical applications (SN: 10/23/10, p. 11).