It’s so simple, it almost seems magical. Leaves take in sunlight, convert it to sugars and starches, and the plant feeds itself and becomes the first link in a food chain that reaches all the way to the apple you chew and swallow on the way to the big game.
So, how does it work? Chemistry silly. In the case of plants, the leaves contain chlorophyll, which, when combined with water, enables the plant to photosynthesize, which is the process I described above. It’s not really that simple, but the lack of moving parts makes it seem so, and it certainly is quite elegant.
What happens when the chlorophyll goes away? Well, the plant enters a dormant phase, and the loss of the green pigment leaves behind (no pun intended) the beautiful colors you see when autumn rolls around each year. It’s early in the northern hemisphere to think about autumn, but for those of you south of the equator, have a look at what’s coming. Leaves changing from green to red, orange, yellow, and purple.
We are into week nine of the weekly, online, video series “Chemistry Now,” and the chemistry of the garden works its way back through the flow of energy to chlorophyll and photosynthesis as a source of interesting video and lessons. As we’ve written before, please view the video, try the lessons, and let us know what you think.
Photo: Chrissy Ferguson
Through the Chemistry Now series, NSTA and NBC Learn have teamed up with the National Science Foundation (NSF) to create lessons related to common, physical objects in our world and the changes they undergo every day. The series also looks at the lives and work of scientists on the frontiers of 21st century chemistry.
Video: “The Chemistry of Green” outlines the role of chlorophyll in photosynthesis, and explains why plants are green.
Middle school lesson: Chlorophyll Chromatography gives students an understanding of paper chromatography, allowing them to separate a mixture of pigments extracted from leaves.
High school lesson: Like the middle school lesson, this version of the lesson introduces the process of chromatography, but in this experiment, they separate a mixture of photosynthetic pigments extracted from leaves.