jazz hands in carbohydrates!

I so enjoy teaching this class!
The Chemistry 1152 course is my favorite for a variety of reasons, but I especially like it when we hit the biochemical compounds!
Tonight, we finished up the disaccharides, paying special attention to their basic components, their glycosidic bond, their structure, and the presence of any jazz hands.
That's right, I said it: jazz hands!!!
Not all molecules have them, but some do.

No jazz hands here.
This is the disaccharide known as maltose, with its free carbon having the alpha (α) configuration for its alcohol group.
(That would be the hydroxide on the rightmost carbon on the right side of the molecule. If the hydroxide had been in the "up" position, that would have made it β.)
Maltose, which is grain sugar, is composed of two glucose molecules joined by an α-1,4 glycosidic bond.
(That would be the ether between the rightmost carbon on the left side of the molecule and the fourth carbon on the right side of the molecule.)
The two glucose molecules appear to be holding hands, don't they?
Oh, how very sweet...
all puns intended!
(smile)

No jazz hands here, either.
This disaccharide is lactose, again with its free carbon having the alcohol in the α configuration.
Otherwise known as milk sugar, we see one molecule of glucose (in purple) joined to one molecule of galactose (in blue).
Between the two monosaccharides is a β-1,4 glycosodic bond.
This time, it seems as though the glucose is dragging along the galactose, much as a parent might tug on the hand of a reluctant child.
Not quite so sweet a picture, is it?
(smile)

Finally, some jazz hands!
Sucrose, or table sugar, doesn't have any alcohol on its rightmost carbons, so it lacks the α or β designation.
This disaccharide also contains glucose (again in purple), as well as fructose (in green), with the two joined by an α,β-1,2 glycosidic bond.
(So we see the link is the ether between the first carbon of the glucose and the second carbon of the fructose.)
Now, the resulting molecule looks like a giant cake in a grocery cart!
Something for your sweet tooth, for sure!
(smile!)

Confused about the jazz hands?
Let me show you this way.

This is the Haworth structure for glucose,
an aldohexose.
Carbon One is the rightmost carbon.
We see its alcohol in the α position.
Carbons Two, Three, and Four
are the identifiers and have their
alcohols in an alternating
down-up-down configuration
which corresponds to the
right-left-right arrangement
seen in the Fischer projection
of the molecule.
Carbon Six is the one in the air,
waving like it just doesn't care.
(smile)

This molecule is kin to the preceding, also containing six carbons, with its alcohols in the same arrangement for Carbons Three and Four as seen above.
Fructose, however, is a ketohexose, as its carbonyl was on Carbon Two instead of Carbon One.
In its ring form, then, it has two dangling, alcohol-laden carbons!
Now, both Carbon One
and Carbon Six
are waving hands in the air
like they just do not care!
Jazz hands!