At Phys.org: Alpine lake bacteria deploy two light-harvesting systems
Christopher Packham writes: Though humans, along with other vertebrate and invertebrate organisms, don’t photosynthesize, we’re definitely the downstream beneficiaries of the life forms that do. Phototrophic organisms at the bottom of the food chain convert abundant sunlight into the energy that ultimately powers all other life. The two metabolic systems for harvesting light energy are fundamentally different. The most familiar is the chlorophyll-based photosynthesis by which plant life uses light to power the conversion of carbon dioxide and water into sugars and starches; the other system consists of proton-pumping rhodopsins. Microbial rhodopsins, retinal-binding proteins, provide ion transport driven by light (and incidentally, sensory functions). It’s a family that includes light-driven proton pumps, ion pumps, ion channels and light sensors. Microbial rhodopsins are Read More ›