Integrated SequencePhysics Chemistry Organic Biology

Web Resources

  click if a link is broken

Special points of emphasis

Reactions of Alcohols and Ethers

Reactions of Aldehydes and Ketones


Carbohydrates are aldehydes or ketones with multiple hydroxyl groups. The composition of C, H, and O in a carbohydrate is in the ratio (CH2O) which is the source of the name (hydrate of carbon). The importance of aldehyde/ketone chemistry for understanding carbohydrates is obvious. For example, the reaction through which a straight chain sugar assumes the ring form is hemi-acetal formation.



Biochemists generally do not employ the Cahn-Ingold-Prelog system to represent carbohydrate stereochemistry, relying instead on Fischer projection formulas and the D,L system of notation, which relates the stereochemistry of carbohydrate carbons to the configuration of (+)-glyceraldehyde. Although the D,L system finds its way onto almost every MCAT, but not in terms of direct application. You probably would never need to relate a form to (+)-glyceraldehyde on the MCAT and assign the nomenclature yourself. When the D,L system is on the MCAT, it is almost always serving as a comprehension stumbling block. If you understand the basics, you won't have a problem. Of the hexoses (glucose, galactose, fructose, etc.), only the D isomers are naturally occuring.

The WikiPremed MCAT Course is a free comprehensive course in the undergraduate level general sciences. Undergraduate level physics, chemistry, organic chemistry and biology are presented by this course as a unified whole within a spiraling curriculum.

Please read our policies on privacy and shipping & returns.  Contact Us.
MCAT is a registered trademark of the Association of American Medical Colleges, which does not endorse the WikiPremed Course.

Creative Commons License
The work of WikiPremed is published under a Creative Commons Attribution Share Alike 3.0 License. There are elements of work here, such as a subset of the images in the archive from WikiPedia, that originated as GNU General Public License works, so take care to follow the unique stipulations of that license in printed reproductions. You can use the resources here for commercial or non-commercial purposes, but please give attribution and a link to the production credits and edit history of the resource. For the works here which began as my individual work, please attribute "John Wetzel, an author at".