Journal Entry
So, the undersides of my quartz rocks are green - but how do we know it's chlorophyll? Some minerals are green.
It looks green, but is it chlorophyll?
University of Nevada graduate student Lauren Lacroix kindly let me use her Ocean Optics USB-4000 visible/near infrared spectrometer to make sure. This instrument is simple: you shine light on the rock and analyze the spectrum of the light that reflects off it. If it contains chlorophyll a (there are several kinds of chlorophylls and other photosynthetic pigments) then the spectrum shows a big peak in a characteristic place.
A green notebook cover doesn't show a peak in the right place on the spectrum to be chlorophyll
Chlorophyll a is the most common photosynthetic molecule. My rocks do indeed have chlorophyll a. A green notebook cover showed no such peak.
That really big peak on the graph to the right of center proves there's lots of chlorophyll.
Tomorrow we will be making batteries out of bacteria and mud!
There are all kinds of projects going on here all day