[Sca-cooks] Left=hand sugar

[Randy Goldberg MD]

> Mmmm, I wonder if this is l-glucose, as opposed to d-glucose, more
> commonly known as dextrose. Dextrose is a glucose molecule with an extra
> water molecule added at a right angle. That right angle is the reason
> for the dextro- prefix. All I recall of l-glucose is it had a respective
> left hand turn in the molecule. But that 'left-hand sugar' may have it's
> left hand turn either in the glucose molecule itself, or in the attached
> water molecule.

Sorry, you're mistaken in your definitions. Most biological molecules have
an asymmetry to them - it has to do with the geometric shape of a carbon
atom when it's fully bound. Solutions of biologic molecules cause polarized
light to rotate when passed through them. L compounds rotate the light to
the left (levo), while D compounds rotate the light to the right (dextro).
D-glucose, or dextrose, rotates polarized light to the right when the light
shines through it. The specific orientation of chemical moieties around the
carbon atom is defined differently, and does not correlate directly with the
substance's polarity (the R/S definition system used to describe structure
is arbitrary).

That being said, we are probably talking about sucrose made with L sugars.
Common table sugar, or sucrose, is composed of two linked simple sugars,
hence the term "disaccharide". Sucrose is composed of one glucose and one
fructose. Two glucose molecules linked together form maltose, and so on.