Energy Under a Microscope

Hi all,

It's a snowy day in Chicago, but we made it here for the holidays and hopefully things A) leave us with a white Christmas and then B) clear up before I head back to work in DC on Monday. This morning Miss B and I bundled up for a sledding attempt. The hill was just right but the wind and cold truncated our outing. We did have fun following tracks in the yard, something B has become fond of. If you know the children's book "Who Pooped In the Park" you'll get the idea. While we didn't see any squirrels or bunnies we found lots of evidence. We even found some evidence of #1 and #2 so we agreed that we'd 'seen' lots of animals. Good times with my little girl. Just now B & I made cookies, so with the smell of triple chocolate/coffee cookies wafting up from downstairs and the sight of softly falling snow out the window I want to continue with my tour of NREL last week. I believe I left off with the Wednesday afternoon solar tour.
Thursday was all about the VIP tour of the lab.
It began with Todd showing me his domain at NREL, the entire microscopy lab. He works on biofuels, mainly the conversion of biomass to ethanol. There are all manner of crops and farming leftovers that can be converted to ethanol. If you will remember your biology 101 lessons (for those of you who've taken bio, that is, Dad!) you know that plants have no bones but are 'solid' because of the cell wall surrounding each cell. You might even remember that plants' cell walls are made up of cellulose and that cellulose is simply a loooooooong chain of glucose molecules. Feed that sugar to yeast and "Ta-DA!!", you get ethanol. Trouble is, that cellulose is a tough nut to crack. The term I heard repeatedly from various scientists in the biofuels division was "recalcitrant cellulose".
So the microscopy lab works on figuring out the exact 'landscape' of cellulose in crops ranging from poplar trees to begasse (left overs from pressing the sugar from sugarcane) to corn stover (everything of the corn plant save the cob and kernels). They also use the fabulous microscopes to figure out the structure of the various enzymes they isolate which break down cellulose. The AFM - atomic force microscope was particulary interesting. Imagine a REALLY small needle they can 'drag' across the surface of say, cellulose. This sends signals to the computer to create a surface map of the structure. And to make it cooler still, they can tag the end of the needle with an enzyme. The needle now not only reveals the 3-D surface but also reacts with specific chemicals as it drags across the surface yielding a biochemical facet to that map.
I was shown how they prep samples for use in the electron microscopes. When we walked into the neighboring room I did a little geeky happy dance and said "ooh, an SEM. I used one of those in my research last summer". Todd noted this and when we sat down to look at some corn stover under the scope he let me drive. Really. It was like learning to drive on a '73 Honda Civic hatchback and then having someone offer to let you drive their Maserati. It ranks up there with the time in Peace Corps when the pilot, busy with paperwork told me I could fly a while as we cruised over the jungle on the way back to my site. Good times. As a quick 411, and SEM is used to look at surfaces while a the TEM (transmission electron microscope) looks "inside" a cell, or??. So I got to zoom in on the corn stover down to the point where we were looking at the pores which lead inside a cell. Never ceases to amaze me the worlds revealed through microscopy.
Okay, I've gone on long enough for now and will continue with more tour highlights next time, including the "brewmeister" and melting bricks. I hope you all are enjoying preparations for the holidays with cookies, friends and family all around.
-J