Green Plants, Red Glow: Chlorophyll’s Red Fluorescence as a Signal of Photosynthesis, Agriculture, and Global Ecology

The activity provides an anchor for teaching photosynthesis in a biological, agricultural, and ecological context and for inspiring students to see plants as fascinating and vital to life on Earth. Background information Photosynthesis is often summarized by the equation [6 CO2 + 6 H2O + light ^ C6H12O6 + 6 O2], which of course is correct, but this focus on input (carbon dioxide, water, and light) and output (carbohydrate and oxygen) diverts attention from the essential role of chlorophyll. Chlorophyll is located in chloroplasts-subcellular factories for solar energy utilization-which in turn are located in plant cells. Fluorescence intensity decreases as the flashlight moves away from the container. Because chlorophyll absorbs more strongly in the visible region than in the ultraviolet, a flash- light is superior than a (ultraviolet) black light to induce fluorescence.