Cellulose molecule thickness
Can anyone tell me the thickness of a molecule of cellulose?
Some of our students are trying to figure out how many molecules thick
a piece of paper would be!
You can get a crude estimate by knowing that cellulose is a
polymer of glucose, which is a puckered six-sided ring of five carbons
and one oxygen, plus some short side groups. The smallest dimension of
the ring can be estimated by drawing the ring from the side. You'd see
a zigzag, like a sloppy letter Z on its side, made up of three joined
line segments going up, down, and then up. These are the carbon-carbon
bonds in the ring seen from the side (you can only see three of them
because the other three are behind the front three). The angle between
the bonds is about 110 degrees. The length of the bonds is about 1.5
angstroms, or 0.15 nanometers. From this and the drawing you can estimate
how far it is across the ring. Add on the diameter of a carbon bonded to
two hydrogens (CH_2 group), about 4 angstroms or 0.4 nanometers.
Click here to return to the Biology Archives
Update: June 2012