In Handout 2 on polysaccharides, the maltose sugar structure suggests
that the second glucose can be either alpha or beta. Is this because of the
fact that the OH on C4 for both beta and alpha glucose are equatorial out?
But if the second one is a beta, wouldn't the second linkage be a beta bond
instead of alpha? Then is maltose made of alpha or beta linkage?
The right hand glucose is free to assume the straight chain form and the ring
again and agian, so it is in the same equilibrium with respect to C1 as the
free sugar.
The anomeric C1 OH orientation is independent of the situation at C4.
The enzyme that catalyzes the formation of starch (which is what you are
starting to do if add a third sugar to maltose) will only accept an alpha
orientation at C1. So it waits for that kind of ring to form (not long) before
it springs into action.