chem quote....

My name is Bond... Ionic Bond... Taken Not Shared...

Powerpoint for Disaccharides & Polysaccharides

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Powerpoint for Reactions of the Hexoses

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Molecular Structures of the Aldoses and the Ketoses

Here's the chart that illustrates the molecular structures of the D-aldoses. The positions of all hydroxyl groups (-OH) connected to the chiral carbon atoms are reversed for the L-aldoses.

The aldose is named a D or L enantiomer based on the position of the -OH group in the chiral carbon atom farthest from the -C=O (carbonyl) group. For the D-aldoses, -OH is on the right side of the C-atom. The L-aldoses will have the -OH on the left side of the C-atom. The names, of course, will be the same...

Here's the chart of the L-aldoses I have prepared by flipping horizontally the image/chart above. Notice the reversed positions of all the -OH groups in the chiral centers of the molecules.

Since dihydroxyacetone does not have a mirror image (due to the absence of a chiral C-atom in its structure), mirror-imaging will start with the tetroses for the ketoses. The left side of the chart for the ketoses should show the structures of the D-ketoses, the right side will show the structures of the L-ketoses. The chart below shows only the molecular structures of the D-ketoses...

Just click on the images to enlarge them...

carbohydrates...