Starch and cellulose are both produced by plants, yet one is easily digested by animals and the other is not. Discuss the differences in the structures of these two molecules and how this may impact whether they can be digested.
Starch and
cellulose have the same substance but different structures. They are both
polysaccharides. The basic unit of a polysaccharide is the glucose. Glucose,
which contains carbon, hydrogen, and oxygen, have two forms. The alpha-glucose
with an alcohol group attached to carbon 1 is down and the beta-glucose with
the alcohol group attached to carbon 1 is up. Starch is the alpha-glucose while
cellulose is the beta-glucose. Starches are linked into a straight chain whereas
the cellulose are connected like a pile of stack paper. When the human body
eats starch, it can digest the starch but not the cellulose because it has no
enzyme that can break it down.